On the Effect of Gender and Years of Instruction on Iranian EFL Learners' Collocational Competence

This study investigates the Iranian EFL learners' Knowledge of Lexical Collocation at three academic levels: freshmen, sophomores, and juniors. The participants were forty three English majors doing their B.A. in English Translation studies in Chabahar Maritime University. They took a 50-item fill-in-the-blank test of lexical collocations. The test included five types of collocations: verb-noun, adjective-noun, noun-verb, adverb-adjective, and verb-adverb. Descriptive statistics, t-test, and One-way ANOVA were employed in the data analysis. According to the results, Iranian English majors are weak in lexical collocations, answering just more than 50% of the questions. A significant difference was found among the performance of the students at three academic levels, but there was no significant difference between boys and girls in their knowledge of lexical collocations. While noun-verb collocation was revealed to be the easiest type of collocation, adverb-adjective collocation proved to be the most difficult type. These findings have immediate implications for language learners, EFL teachers, and material designers.


Introduction
Learning a language is the result of many competences grouped together; hence, we should work on all these aspects to learn the whole language.Unlike grammar, vocabulary has long been ignored in EFL classes.It has always been taught through other skills, whereas grammar has been taught as a separate skill, and has pushed vocabulary to an inferior position.Students are taught a lot of grammatical rules as if teaching a language equals teaching its grammar.Even some old approaches which have focused on vocabulary teaching have introduced words only in vocabulary lists, and students have been told to learn them by heart, a technique which has proved insufficient.
Although some researchers such as Brown (1974) cautioned our ESL/EFL field about the danger of ignoring vocabulary instruction, it was not until the 1990s that scholars recognized the importance of vocabulary in teaching English as a second or foreign language, and devoted themselves to the improvement of vocabulary instruction."While without grammar very little can be conveyed, without vocabulary nothing can be conveyed."(Wilkins, 1972, p. 111).This argument has been supported by many researchers in the field of second language acquisition who have stressed the significance of vocabulary and agreed that vocabulary is equally, if not more, important than language structure in language acquisition (Krashen, 1988).
Within the area of vocabulary research, researchers have underlined the importance of word combinations, which are usually referred to as formulaic language.They argue that these formulaic expressions are common in language discourse and distinguish the speech of native from non-native speakers (Conklin & Schmitt, 2007).For instance, Erman and Warren (2000) found that formulaic language constitutes approximately 59% of the spoken English discourse and about 53% of the written English discourse.Moreover, the raters in Forster's study (2001) classified 32.3% of the unplanned speech of the non-native speakers as formulaic language.Formulaic sequences facilitate language development for first language learners, and second language learners since they provide learners with the raw material that helps them improve their language (Bardovi-Harlig, 2002).
We have always heard the expressions "communicative and linguistic competence" but "collocational competence" is usually an unfamiliar phrase for most EFL learners and even for teachers.This concept was coined by Lewis (2000) who said: "We are familiar with the concept of communicative competence, but we need to add the concept of collocational competence to our thinking".(p.49) Collocational competence is "the ability to accurately combine chunks of language thus enabling production of fluent, accurate and stylistically appropriate speech."(Heikkila, 2005).Firth (1957) was the first scholar to claim that one knows a word by the company it keeps.He believed that if a student knows the other words with which a lexical item can be used, he or she knows that word.And, on the contrary, a student may not be thought of as knowing the language and using it properly if he or she knows the meaning of all entries in a dictionary but has problems in using some seemingly synonymous words.Lewis (1997) contended that competence and proficiency in a language equals acquiring fixed or semifixed prefabricated items.It is, therefore, apparent that to achieve competence, the learner will need to master semifixed and fixed expressions.Knowledge of collocations affects the production proficiency (Nattinger, 1980;Smadja, 1989), and the comprehension of input (Brown, 1974;Kelly, 1991).Jack Richards (1983) further pointed out that "where segmentation is difficult, comprehension is also difficult" (p.220).In other words, a language learner may encounter difficulty in performing inference or comprehension if he is unable to segment the discourse into appropriate chunks (Berne, 2004).

Collocation in Language Learning
Besides, it is believed that automation of collocations helps native speakers to fluently express themselves since it provides 'chunks' of English that are ready to use.Second language learners, however, do not possess this automation, and as a result make non-native errors when producing utterances or writings (Lewis, 2000).Besides, they use inappropriate word combinations when they write to the extent that their writing is not natural and native-like.Hill (2000) contended that students with good ideas often lose marks because they do not know the most important collocations of a key word that is central to the topic they are writing about.Therefore, their writing is full of "miscollocations" that make it sound unnatural.In order to achieve native-like competence and fluency, second language learners need to know that an important part of language acquisition is to understand and produce collocations.Lewis (2000) argued that language acquisition takes place when the learner is able to analyze the language into lexical 'chunks'.Another reason why collocations are important in learning a language is that words are learned and used in context.Knowing a word includes knowing how and where we can use that word (Phythian-Sence & Wagner, 2007) and without successfully employing its companions, out-of-context learning of word lists will be ineffective.

Previous Studies
The fact that L2 learners have problem with lexical collocations is widely accepted (Bahns & Eldaw, 1993;Granger, 1998;Nesselhauf, 2005).Bahn and Eldaw (1993) investigated advanced German learners' productive knowledge of 15 verb + noun collocations and found that the translation of verbs that are part of collocations poses many more problems than the collocations of other lexical items.They also contended that collocation knowledge does not develop alongside general lexical knowledge.Zhang (1993) also conducted a study about the correlations between the knowledge and use of collocations and the quality of freshmen's writing.The first conclusion was that "collocational knowledge is a source of fluency in written communication among college freshmen".Secondly, "quality of collocational use distinguished between Good and Poor college freshmen writings as well as between native and non native college freshmen writings".In another study, Farghal and Obiedat (1995) analyzed the collocations produced by 57 Arabic university students of English.The conclusion drawn in this study was that L2 learners cannot cope with collocations.What all these scholars unanimously believe is that collocation production presents a problem for second language learners and is that learners use generally fewer collocations than native speakers.
Different from previous studies where mainly the relationship between the knowledge and learning of collocation was explored, Al-Zahrani (1998) carried out a study to investigate the differences in the knowledge of English lexical collocations among four academic levels of Saudi EFL students and the relationship between the knowledge of lexical collocations and these participants' general language proficiency.In this study, the collocational knowledge of 81 male English majors was measured by a Test of Collocations.The test includes 50 verb-noun combinations with the verb missing but the first letter or phoneme given.The participants' general English proficiency, in the meantime, was elicited by completing a writing test and an Institutional Version of TOEFL Exam.Al-Zahrani found that there were significant differences in students' knowledge of collocations in the comparison between the freshmen and sophomores and the comparison between the juniors and seniors, while there was a slight difference between the sophomores and juniors.In addition, there was a strong relationship between the participants' knowledge of collocations and their overall language proficiency.Al-Zahrani also pointed out that the writing test was a good predicator of students' knowledge of collocations.
In one of her collocation studies, Liu (2000) led the field in investigating the effects of collocation instruction on students' writing performance.Forty-nine freshmen English majors at a Taiwanese university participated in the study.During an 18-week semester, in a three-hour weekly class, Liu (2000) gave her students a series of twenty-minute mini-lessons on collocations (e.g., the introduction of six major lexical collocation patterns, collocations without direct L1 equivalents, and de-lexicalized verbs as collocates of nouns).To assess their writing ability and use of collocations, the subjects were asked to write a composition in class at the beginning and the end of the semester without using a dictionary.The two compositions were analyzed and compared for the patterns of acceptable and unacceptable lexical collocations.It was found that the students in the second composition generated a greater number and variety of acceptable lexical collocations although they did not improve much in their writing of the second composition.
To assess Taiwanese EFL learners' collocational knowledge, Wu (2005) designed a fill-in-the-blank test for 178 English majors (59 freshmen, 48 sophomores, 32 juniors, and 39 seniors) at a university of science and technology.This test consisted of 50 verbs chosen from the list of 1000 English words that should be learned by junior high school students provided by the Ministry of Education in Taiwan.She restricted the scope of her investigation to only verb-noun lexical collocations where subjects had to supply the verb (e.g.Never ____ a bath when you are sleepy.Falling asleep in a bath is very dangerous.Correct answer: take) because she believed, according to the previous studies she reviewed, this type of collocation causes more problems for EFL learners.Wu (2005) reports that the higher academic level the students are the better their collocational knowledge.Significant differences in their mean scores were found between seniors and each of the other levels (larger between seniors and freshmen and also between seniors and sophomores, p < .001,than between seniors and juniors, p < .05).However, from their combined average scores of 58.08% accuracy on the test, she concluded the Taiwan EFL students at science and technology universities have insufficient knowledge of collocations.Her findings imply that students' collocational knowledge does not develop in parallel with single-word vocabulary knowledge, which means that even though they acquire single-word vocabulary they may not acquire the collocations associated with those words at the same time.Thus, she recommends that explicit collocation instruction be implemented in the EFL classroom to raise learners' awareness of them.She points out another factor which might affect learners' collocation learning and recommends "textbook designers should emphasize and highlight collocations in textbooks" (p.93).

Statement of the Problem
Collocations are one of the areas that produce problems for learners of English as a foreign language, and Iranian learners of English are by no means an exception.Sadeghi, K. (2009) suggests that a significant part of Iranian EFL learners' problems with producing the language, especially at lower levels of proficiency, can be traced back to the areas where there is a difference between source-and target-language word partners.Even though having learned and memorized a large vocabulary, Iranian EFL learners encounter difficulties in properly combining words in speech or writing.It is argued that the problem for advanced learners is not so much with encountering vast numbers of new words as with working with already half-known words and exploring their collocational fields (Hill, 1999).Another common problem among Iranian EFL learners is that they cannot construct a good and natural speech and writing, even though they possess good grammatical competence.They can get high grades in grammar tests, but regrettably their writing is full of wrong combinations of words.Furthermore, quite a few surveys have revealed that advanced EFL learners' English collocation competence is significantly inferior to that of native speakers.

Significance of the Study
Most studies conducted in Iran have investigated other aspects of collocation instruction such as: the effect of collocation instruction on writing (e.g., Ghonsoli, Pishghadam, & Mahjobi 2008), or the effect of L1 on collocational knowledge (e.g., Sadeghi, K. 2009), or have included only one type of collocations (n+v) (e.g., Hosseini & Akbarian, 2007).
This study is significant in different ways.First of all, it is the first study which aims to comprehensively collect data regarding Iranian EFL learners' collocational competence.Furthermore, the participants are from three different academic levels, freshmen, sophomores, and juniors.Another difference is that both boys and girls are participating in this study.And finally, the collocation test includes different types of collocations.It includes verb-noun, adjective-noun, noun-verb, adverb-adjective, and verb-adverb.

Definition and Classification of Collocation
The concept of collocations was first identified by Palmer (1933), as cited in Nation, 2001, p. 317) as "a string of words that must or should be learned, or is best or most conveniently learnt as an integral whole or independent entity, rather than by the process of piecing together their component parts".However, Firth (1957) is generally credited by most scholars as the researcher who brought collocations into prominence in the linguistic field.
According to Benson, Benson & Ilson (1997), there are two major categories of collocations: grammatical collocations and lexical collocations.They define a grammatical collocation as "a phrase consisting of a dominant word (noun, adjective, or verb) and a preposition or grammatical structure such as an infinitive or clause; examples are "account for" and "adapt to" (p.xv).It consists of 8 subtypes as follows: noun-preposition, noun-to infinitive, noun-that clause, preposition-noun, adjective-preposition, adjective-to-infinitive, adjective-that clause, and verb patterns.On the other hand, Benson et al. (1997) state that lexical collocations "in contrast to grammatical collocations, normally do not contain prepositions, infinitives, or clauses.Typical lexical collocations consist of nouns, adjectives, verbs, and adverbs; examples are: "commit murder" and "fly a kite" (p.xxx).There are 7 types of lexical collocations as follows: verb-noun, adjective-noun, noun-noun, noun-verb, noun-of-noun, adverb-adjective, and verb-adverb.

Purpose of the Study
Although much has been said about the acquisition of collocations by EFL learners who come from various cultural backgrounds in various countries (Gitsaki, 1999), very few studies have explored the collocational knowledge of Iranian EFL learners.Furthermore, as mentioned in previous sections, knowledge of lexical collocations plays a vital role in native-like fluency of EFL learners in speech and writing, and it also influences their comprehension in reading and listening.This study has three different purposes.First of all, it comprehensively scrutinizes the knowledge of lexical collocations among Iranian university students, including freshmen, sophomores, and juniors.The second aim of this research is to find out if the gender of the participants and years of instruction in university influences the students' knowledge of lexical collocations.And finally, it tries to find out what the easiest and most difficult types of collocations for Iranian university students are.To that end, the implementation of the present study at the experimental stage sets itself the goal to shed some lights on the following research questions: 1. How proficient are Iranian university students in English lexical collocations?2. Is there any significant difference between boys and girls in their knowledge of lexical collocations?3. Is there any significant difference between freshmen, sophomores, and juniors in their knowledge of lexical collocations?
4. What is the easiest type of lexical collocation for Iranian university students? 5. What is the most difficult type of lexical collocation for Iranian university students?

Participants and Setting of the Study
This study was conducted in the English Department of Chabahar Maritime University.Forty-three students from the English Department of Chabahar Maritime University were involved in this study.Among these participants, twenty-five of them were males and the other eighteen students were females.All students were enrolled in classes during the winter semester of 2011, a period of 15 weeks.They were at different classes, eleven of them were doing their first year (freshmen), seventeen students were in their second year (sophomore), and fifteen students were in the third year (junior).Their ages ranged from 18 to 23.Their first language is Farsi, also called Persian, which is the official language of Islamic Republic of Iran.They were all doing their B.A. in Translation Studies.Before entering the university, they had received at least 6 years of English instruction, but mostly reading and grammar.

Instrumentation
This study is descriptive in nature.It gives information about the collocational knowledge of the Iranian university students at different academic levels.There is no treatment in this study.Students take a test of lexical collocations and the results are compared between boys and girls, and among freshmen, sophomores, and juniors.The only instrument used in this study is a 50-item fill-in-the-blank test of English lexical collocations.The test consisted of 50 questions, each one with a blank to be filed with the appropriate collocation needed.The test included 5 types of lexical collocations, so there were 10 questions for each type of collocation.According to Benson et al. (1997), there are 7 types of lexical collocations as follows: 1.verb-noun, 2.adjective-noun, 3.noun-noun, 4.noun-verb, 5.noun-of-noun, 6.adverb-adjective, and 7.verb-adverb.But this study included only 5 types of collocations, excluding collocation type 3 and 5. Thus, the lexical collocations studied in this research were: verb-noun, adjective-noun, noun-verb, adverb-adjective, and verb-adverb.The first type of collocations was verb-noun collocation.Thus, in questions 1 to 10, the students had to provide the noun which collocates with the verb given in the sentence, e.g.earn m……….. (Earn money).The second type of collocation was adjective-noun; in these questions the students had to write the adjective needed for that special noun, e.g.g……..shape (Great shape).The third type of collocation tested was noun-verb, where the students had to provide the verb needed for that context, e.g.time f…… (Time flies).The fourth type of collocation was adverb-adjective, e.g.q……….common(Quite common).This time, they had to write the necessary adverb.And the last type of collocation was verb-adverb; where the students had to write the correct adverb, e.g.speak f…….(Speak fluently).Each question was in the form of a paragraph of at least 4 or 5 sentences, with one word missing.The students had to read the questions and guess the correct word needed in that context.In order to help the students have a better guess, the first letter of the word was given to guide them in choosing the suitable word.

Data Collection Procedure and Analysis
The data of this study consists of the students' scores on the test of lexical collocations.There were 50 items in the test, thus the scores of the students ranged from 0 to 50.For most of the questions, there was only one answer since the first letter of the word was given and this limited the number of words they could write.The data were then entered into the computer, using SPSS version 17.To compare the performances of the male and female students on the collocation test, independent sample t-test was used.And to compare the performances of the students at three academic levels of freshmen, sophomore, and juniors, One-way ANOVA was used.

Results
The most important aim of this study was to investigate the knowledge of lexical collocations among Iranian university student majoring English translation.There were 43 university students participating in this study, 11 freshmen, 17 sophomores, and 15 juniors.The descriptive statistics of the performances of students on the 50-item fill-in-the-blank test of lexical collocations are summarized in Table 1.
Generally speaking, Iranian university students could answer just more than 50% of the questions.The mean score of Iranian students on the test of lexical collocations was 25.65, indicating that Iranian university students are quite weak in lexical collocations, since they had studied English for at least 6 years before entering the university.Furthermore, they are doing their B.A. in English Translation Studies, being chosen from among around one million students who participate in the Iranian National University Entrance Exam.
The second point which is worth mentioning is that male students had a better performance on the collocation test, indicating that boys are better language learners than girls, at least in this aspect of language learning, which is quite important.However, this difference does not seem to be statistically significant.The mean score for boys was 26, while girls mean score was 25.16 out of 50.Boys had a better performance than girls in both first-year and second-year class, but female students could surpass boys only in junior class.The biggest difference between boys and girls was found in sophomores where boys' mean score was 24.07, while girls' mean score was just 14.75.
As regards the performances of the students at different academic levels, the results were quite surprising.The best performance belonged to the fresh students whose mean score was 28.54, followed by juniors who had a lower mean score (27.80).The mean difference of 0.74 is not very much, but the fact that freshmen had a better performance than juniors is alarming news for educational authorities in Iran.The least professional group of students in the test of lexical collocations was sophomores, far below others, with the mean score of 21.88.The last important point in this table is the subgroups that had the best and worst performances in the lexical collocation test.Fresh Male students achieved the highest mean scores among the six subgroups, with the mean score of 29.50.The highest score belonged to this subgroup, Kharidar got 41.And finally, the students with the lowest mean score were Female Sophomores (14.75).
To compare the possible difference between the performances of boys and girls in the test of lexical collocation, an independent sample t-test was used, the results of which are displayed in Table 2.The first thing we need to do is to check if variances in the two groups are equal by checking the result of Levine's Test for Equality of Variances.To check this, one should look at the "Sig."row within Levine's Test for Equality of Variances row which is highlighted.If the variances are equal in both groups, then the P-value ("Sig.")will be greater than 0.05.However, if the "Sig."value is less than 0.05, the variances are unequal, and we need to use the Equal variances not assumed column.Since the "Sig."value, here 0.033, is less than 0.05, the variances are not equal, we need to use the Equal variances not assumed column.As indicated in this column, we can see that there is no significant difference between the performances of boys and girls in this test.Thus, although there is a slight difference between the boys and girls performance, this difference is not statistically significant.The important point is that both of them are weak in this aspect of language learning.The next research question was about the differences in the collocation test among students at three academic levels.There were students from first year, second year, and third year participating in this study.Since there are three groups of students, to compare their performances on the test, One-way ANOVA was used in this stage.All the students' scores were subjected to a One-way ANOVA, and the summary of results is shown in Table 3.If there were significant differences among the performances of these students, then a post-hoc Scheffé-test would be run on the data to tell us where the differences are significant.As it can be seen in Table 3, the F-observed value is 4.406.This amount of F-value is greater than the critical value of F at 2 and 40 degrees of freedom, i.e. 3.23.Since the observed F-value exceeded its critical value, it can be concluded that there are significant differences among the performances of students at three academic levels of freshmen, sophomores, and juniors.
The post-hoc Scheffé test was run to compare the mean scores of the three academic levels of freshmen, sophomores, and juniors on the test of lexical collocations.According to the results displayed in Table 4, the mean difference of 6.66 (p < .05)indicates that there is a statistically significant difference between the freshmen' and sophomores' mean scores on test of lexical collocations.Thus, the freshmen outperformed sophomores on the lexical collocations test, even though sophomores are generally supposed to be at a higher level of proficiency since they had studied English more.The fact that collocational knowledge has not improved with the years of instruction in universities is not only surprising, but also depressing for teachers and authorities.More importantly, freshmen had a better performance than even juniors, although not statistically significant.As indicated in the table, there is no statistically significant difference between freshmen and juniors.The last point about the table is that the mean difference of 5.91 (p < .05)indicates that there is a significant difference between juniors and sophomores, with juniors outperforming sophomores.Therefore, freshmen who studied English less than others had the best performance in this test, followed by juniors and sophomores.
As mentioned before, there were five types of lexical collocation included in this study.The first type of collocations was verb-noun collocation.Thus, in questions 1 to 10, the students had to provide the noun which collocates with the verb given in the sentence, e.g.earn m……….. (Earn money).The second type of collocation was adjective-noun; in these questions the students had to write the adjective needed for that special noun, e.g.g……..shape (Great shape).The third type of collocation tested was noun-verb, where the students had to provide the verb needed for that context, e.g.time f…… (Time flies).The fourth type of collocation was adverb-adjective, e.g.q……….common(Quite common).This time, they had to write the necessary adverb.And the last type of collocation was verb-adverb; where the students had to write the correct adverb, e.g.speak f…….(Speak fluently).
The fourth research question asked: What is the easiest type of collocation for Iranian university students?According to the statistics in Table 5, Iranian university students had their highest mean score in collocation type 3 (noun-verb-bolded in the text), where they had to provide the verb-part in these sentences.This type of collocation is also the easiest type of collocation for all the five groups (males, females, freshmen, sophomores, and juniors) and six subgroups (male freshmen, female freshmen, male sophomores, female sophomores, male juniors, and female juniors) of students in this study.Furthermore, this collocation type was the only type in which five students could correctly answer all the ten questions in the exam.Poorjam and Aghajani (juniors), Farrokhi, Harati, and Mollazehi (fresh students) were the five students who could correctly answer all the ten question of the noun-verb lexical collocations in the test.As a result, it goes without saying that this type of collocation is the easiest type for Iranian university students, here English majors.
And finally, as it is displayed in the table and bolded, the most difficult type of lexical collocation for Iranian English majors is Type 4 (adverb-adjective), where the adverb was deleted and the students had to provide the proper adverb for the adjective in question.Again, this type of collocation was the most difficult type of collocation for all the five groups (males, females, freshmen, sophomores, and juniors) and five subgroups (male freshmen, male sophomores, female sophomores, male juniors, and female sophomores) of students in this study.Students' mean score on this type of lexical collocation was 4.28.The only subgroup which acted differently from all the other groups and subgroups was fresh females.These students had exactly the same mean on Type 4 and Type 5. Thus, the most difficult types of collocations for fresh females were adverb-adjective, and verb-adverb, with the mean score of 4.28.The second most difficult type of lexical collocation for Iranian EFL learners was Type 5, verb-adverb.Thus, what is really problematic for these learners is the adverb, since this is the adverb which should be provided in these types of collocations.

Discussion and Conclusion
This study found out that the collocational knowledge of Iranian English majors is quite weak, as mentioned before; they could answer just more than half of the questions.Their mean score was 25.65 out of 50.This is quite disappointing since they had studied English for at least 6 years at junior and senior high schools, and are students majoring at English translation studies.Furthermore, they have been chosen from among around one million students who take part in the Iranian National University Entrance Exam annually.They are freshmen, sophomores, and juniors studying English at university for one, two, and three years respectively.This seems to be, to some extent, due to the fact that teachers do not pay enough attention to collocation teaching, and to a larger extent, to the inadequate emphasis given to collocational knowledge in their books, and the instructions they receive.Moreover, collocations have never been a part of teaching in Iran.However, this is a common problem in English as a Foreign Language teaching.This conclusion is shared by many scholars who unanimously believe that EFL learners are weak at collocations (Bahns & Eldaw, 1993;Granger, 1998;Nesselhauf, 2005).This is also in line with the findings of Hosseini & Akbarian (2007) in which Iranian students' mean score on the test of Noun-Verb collocation was 20.80 out of 50.They believed that collocation seems to be a difficult aspect of vocabulary knowledge for Iranian language learners and it is apparently gained at the later stages of language learning.It might be the case that the learners might not be familiar with the many uses and senses of the most highly frequent words in terms of differing contexts.It was shocking that students did not know what lexical collocation means in English, or that there is a dictionary of collocations available.No Iranian student uses collocation dictionaries in his writing classes, and to make the matter worse, no teacher encourages them to do so.Translation students pass courses related to the translation of idioms, and phrasal verbs, but no course is dedicated to collocations.Nonetheless, collocational knowledge has been shown to influence the production and comprehension of the language profoundly.Therefore, it is strongly advised that Iranian EFL teachers incorporate collocations into their lesson plans.Taking the studies conducted so far and the findings of this research into account, it is suggested that learners should be exposed to the target language in a way that their consciousness is raised so that they acquire some degree of collocational competence.While there is no doubt that enlarging vocabulary size is vital, much is still left to be dealt with concerning learners' qualitative knowledge of words.Therefore, there should be a balance of quality and quantity of word knowledge in our curriculum.Material developers should incorporate collocations into their books, and give exercises for students to master them.
A further finding deserving some consideration is that university students seem to lose their collocational competence as they move toward later years of study.As might be expected, juniors and sophomores should possess a better knowledge of lexical collocations due to the fact that they have had more exposure to English, but this is quite opposite to what happened in the study.In this study, freshmen had the highest performance, followed by juniors and sophomores.There are different reasons which might justify this.As mentioned above, in Iranian universities and English classes, there is no course related to collocation teaching, there is no exercise related to collocations in the books, teachers are not told to focus on this aspect of language, students do not know what collocation is, or how important it is.Another reason why freshmen had a better mean score is that most of these students have been to English Institutes before coming to university.The last reason might be that students have 3 reading courses in the first terms of their studies, so they deal with different types of texts and do vocabulary exercises.But later on, students' courses are all about translating different texts; the only thing they do is to read the text quickly, and search for Farsi equivalents.They do not pay much attention to the source language vocabulary, since there is a dictionary right next to them all the time.
It was also revealed that collocation type 3 (noun-verb) was the easiest type of lexical collocation for Iranian students.In this type of collocation, students had to provide the verb which could be used with a special noun, e.g.telephone rings, snow falls, tree grows .The first reason might be that it is quite natural and logical to have a special verb for a noun in every language, since dog does not meow, it barks, ice does not vapor, it melts.In other words, this concept is present in Farsi language which is the mother tongue for Iranian students, and all those collocation had an exact counterpart in Farsi.Therefore, the role of the mother tongue is the facilitating factor which resulted in this high performance.Sadeghi (2007) came to the same conclusion that learners are most likely to succeed in cases where they positively transfer their linguistic knowledge of the L1 to an L2 context.Since there is a one-to-one relation between Farsi and English in this regard, students can answer these questions easily.
Type 4 collocation, adverb-adjective, was revealed to be the most difficult type of collocation for Iranian university English majors.In this type of collocation, students had to provide the adverb of the collocations, (highly successful, totally different, fairly easy, quite common, totally wrong, extremely dangerous, completely safe, deadly serious, greatly interested, and terribly afraid).As regards this type of collocations, Farsi speakers rarely use adverb to modify adjectives.There are two adverbs which most of the time play this role in Farsi, ‫-ﺧﻴﻠﯽ‬ ‫.ﮐﺎﻣﻼ‬These two adverbs are the equivalents of very, completely or totally.As it can be seen, these words are repeated three times in the above examples.Thus, although the words used in these examples are different, their meanings overlap to a great extent.Iranian speakers use very ‫,)ﺧﻴﻠﯽ(‬ instead of highly, fairly, quite, extremely, and terribly when speaking Farsi.So, quite contrary to the previous type of collocation, there are not different words in Farsi to convey these meanings, and all of them are expressed using two words, ‫-ﺧﻴﻠﯽ‬ ‫.ﮐﺎﻣﻼ‬Even though the first letter was given, some students crossed the letter out and wrote the word completely instead of them.To wrap it up, the knowledge of mother tongue is negatively transferred in these examples, misleading the students. With regard to the difficulty of collocations for Iranian EFL learners, learners are in dire need of more practice producing collocations.Also, they should receive as much collocation input as possible.According to Krashen (1988), the more word input language learners perceive, the more productive of them they become, which can be true in the acquisition of collocations as well.Generally, the results highlighted the important role that learners' first language plays in the acquisition of L2 collocations.So selecting and teaching collocations should be done with reference to L1 where learners become aware of the L1-L2 differences and similarities.In teaching collocations, more attention should be given to teaching adjective-adverb, and verb-adverb collocations, which the results showed to be the most difficult type of collocations for Iranian EFL learners, where the focus should be on the adverbs that causes the greatest difficulties.Adding a bilingual glossary of collocations to textbooks is recommended to keep learners aware of the similarities and differences between the first and second language.

Table 1 .
Descriptive Statistics of students' performances on the lexical collocation test

Table 2 .
Independent samples t-test results for the performances of boys and girls

Table 3 .
One-way ANOVA results for the three academic levels on the collocation test

Table 4 .
Post-hoc Scheffé test results for different academic levels on the lexical collocation test *.The mean difference is significant at the 0.05 level.

Table 5 .
Mean scores of students on different types of lexical collocations