Writing Error : A Review of Interlingual and Intralingual Interference in EFL Context

This paper aims to review the theoretical concept of interlingual interference of the mother tongue, Thai to the target language, English and intralingual interference found in EFL student writing in Thai context with the attempt to define the existence of errors according to their sources. This review article also exemplifies some frequent errors normally found in Thai student writing based on three perspectives of interlingual interference; lexical, syntactic and discourse interference and seven aspects of intralingual interference; false analogy, misanalysis, incomplete rule application, exploiting redundancy, overlooking cooccurrence restrictions, hypercorrection and overgeneralization. The pedagogical implication for EFL context is also discussed.


EFL Writing Error
As it is generally accepted that writing in English is a complex process for English as a foreign language learners (EFL), it is not surprising that errors in writing are found as an unavoidable part of EFL student writing.Ellis (1997) notes fossilization of learners' grammar does not occur in first language (L1) acquisition, but is unique in second language (L2) acquisition.Other scholars (Leki, 1990 andZhang, 1995) also address that there are distinctive differences of linguistic knowledge between L2 and L1 writers.The differences may include linguistic proficiency and intuition about language, learning experiences and classroom expectations, a sense of audience and writer, preferences for ways of organizing texts, writing processes and understanding of text uses as well as the social value of different text types (Silva, 1993).
Due to the difficulty the L2 writers encounter when they carry the burden of acquiring English and learning to write simultaneously (Hyland, 2003), students often commit errors occurring as an inevitable part of EFL student writing.Also it is found that EFL writing is generally shorter, less cohesive and fluent, and contains more errors (Hyland, 2003 andFerris, 2002.According to Reid (1993), errors caused from other variables apart from first language interference are generally influenced by overgeneralization and the level of difficulty.According to Lalande (1982), despite the fact that the students have studied certain rules of grammar, "some students exhibit remarkable consistency: they commit the same types of errors from one essay to the next" (p.140).It seems that this sort of undesirable consistency can frustrate both students and teachers alike.
Similar to other EFL students, Thai student writers have the same problems.In a Thai classroom, errors found in written English are apparent among college students.One significant explanation is the differences of the two languages; Thai and English.The differences are found in morphology (e.g., verb, noun), lexis (e.g., word choice, pronoun,), syntax (e.g., sentence structure), mechanics (e.g., punctuation) as well as article and noun endings (e.g., plural/ possessive).
Another major problem found in an English writing by Thai students is the negative transference of the mother tongue, Thai, into the target language.When producing English writing, they have the cognitive process in Thai and usually employ direct translation from Thai to English.As a result, it is generally found that typical Thai students who have been studying English for many years cannot write a short paragraph without making serious grammatical errors (Wongsbhindu, 1997).

Sources of EFL Writing Error
As error can be used to measure the language performance of learners, EFL learners commit their errors as an inevitable part of their output, this problem found in student writing is still a going concern on the body of knowledge in research on EFL learners.According to Reid (1993) error from these learners are "systematic and reasoned" (p.35).Based on these problems, error analysis (EA) has become an essential part in EFL teaching and learning which can examine actual language performance of learners as part of contrastive analysis (Heydari, and Bagheri 2012).This area of error analysis has been a growing research interest conducted with learners in order to examine error found in student writing whether the source of errors was "first language interference" or "developmental" (Reid, 1993: 36).Richards (1971) differentiates three sources of error.The first source of error is called 'interference error', which results from the mother tongue interference.The second source, 'intralingual error', reflects the incorrect generalization of the rules within the target language.The last source is 'developmental errors', occurring when the learners hypothesize about the target language based on their limited knowledge.
The two sources of error mentioned above, intralingual and developmental errors, are found closely related and are sometimes confusing (Schacheter and Celce-Murcia, 1977), these two error sources later are considered to be in the same category, intralingual and developmental errors which refer to the errors occurred when the learners have not really acquired significant knowledge of the target language (Reichards, 1974 cited in Schacheter andCelce-Murcia, 1977).
In response to the previous error taxonomy, Dulay and Burt (1974) distinguish three error categories.These categories are developmental errors, which are considerably similar to L1 acquisition, interference errors reflecting the first language (L1) structure, and unique errors which are not considered part of the two categories.Besides these error categories Stenson (1983cited in Karra, 2006) also defines induced error as the error resulting from the classroom situation; teacher explanation and practice.The source of this error later is defined by James (1998, p. 191) as material-induced errors, teacher-talk induced errors, and exercise-based induced errors which are considered classroom based error.
In addition to language and classroom based errors, James (1998) proposes four sources of errors as 'interlingual and intralingual errors, communication strategy-based and induced errors.
It can be seen that all the above-mentioned studies focus on the sources of errors and provide a distinction between L1 interference error and intralingual error which are considerably useful and informative as a guidance when carrying out this paper.All these studies discussed above are useful and they do not only give insight into how learners learn a second language and the factors that impact that process, but they also provide a better understanding of errors that L2 learners make in the process of second language learning.As this paper is a critical review article not a research article and with the attempt of the author to provide a clear picture of interlingual and intralingual errors in Thai context, some frequent errors committed by the author's EFL student writers as well as by other students which are normally found in Thai context are demonstrated to support the theoretical concept based on James (1998) regardless of the research methodology discussion.

Review of Interlanguage Causes: Interlingual Interference
In regard to the sources of error in EFL writing addressed earlier, interlingual error is found as one of the most important factors affecting deviant problems which result from negative transference from mother tongue, Thai (L1) to the target language, English (L2).According to Bhela (1999), it is obvious that EFL errors result from the word for word translation strategy or thinking in mother tongue language.This is not surprising to the fact confirmed by Brudiprabha (1972) stating, one-third of errors are caused from negative interference of L1.
As the studies related to L1 interference have received considerable attention in Thai context, this section provides a detailed account of errors which are discussed based on three aspects; L1 lexical interference, syntactic interference and discourse interference.

L1 Lexical Interference
According to Sereebenjapol (2003), types and frequency of errors occurring in scientific theses are analyzed to examine the source of errors found in four categories, which are syntax, lexis, morphology and orthography, respectively.It is found that the most frequent local errors are the use of subordinators and conjunctions.The causes of each error vary reflecting on the students' carelessness, incomplete application of rules, and differences between English and Thai.
Thep-Ackrapong (2006) also found L1 lexical interference in collocation.It is stated when Thai students write in English, they directly translate Thai words into English.Subsequently, they use Thai collocation in written form of English to convey their ideas.The examples of this error are the sentence "I *play a computer" which can be corrected to "I work on a computer".
The first language interference is also found in Sattayatham & Honsa (2007).It identifies the most frequent errors.A group of Thai students are required to translate from Thai into English at the sentence level and the paragraph level.The results reveal that the most frequent errors are at the syntactic and lexical levels which lead to overgeneralization, incomplete rule application, and building of false concepts.It is also stated that L1 interference was found as a major cause of the students' errors.
Focusing on L1 lexical interference, Bennui (2008) conducts a study of L1 interference in the writing of Thai EFL students.It discusses the literal translation of vocabulary use from Thai.It is found when the students employ Thai words into English such as "get/ receive, serious, book, meet, use, true, close, change, alone, make and cost" (p.84).However, based on the use of Thai word found in the students' English writing, there was only one Thai word "Tuk-Tuk" (A three-wheel cabin cycle in Thailand) used which pragmatically seemed to be a positive transference as this word is created from the use of the native word.
It can be seen that L1 interference is one of the important factors in EFL writing errors.This coincides with Leech (1998, cited in Dagneaux, Denness, & Granger, 1998 ) stating that students exhibit remarkable lexical errors because the lexis is built up from an open system.The formation of words are irregular and unsystematic (James, 1998).Therefore, unlike grammatical structure, lexis cannot be generalized into any specific rule.
Apart from the studies focused on L1 lexical interference mentioned above, this paper also aims to discuss two main types of semantic errors in lexis based on James (1998).These are confusion of sense relation and collocational error.

Confusion of Sense Relation
The semantic error found in this paper coincides with Tuaychareon (2003) in that the restrictions at the L1 semantic level reflects the writer's semantic competence when writing in English as highlighted in the following examples.

I *play the internet. (*surf)
There is no *day on this mail.(*date) I will *keep money for a house.(*save) The first example above reflects the L1 lexical interference, which is normally found when Thai students use the word "play" for all contexts.It can be seen that instead of the word "play", English has specific words to convey the meaning of doing something for pleasure, acting in a play or film, surfing the internet or tricking somebody for fun.On the other hand, the word "play" (Len in Thai) is frequently used by Thai student writers to refer to all pleasurable activities.Likewise, as found in the words "day" and "keep" which are used in all contexts of Thai student writing, these lexical errors result from their L1 interference and limited semantic competence in English.

Collocational Error
This type of error interfered by L1 is found when the writers use direct translation to form the collocation as shown in the following examples.

He described *about his house." *[Ø]
The example of error found here is the unnecessary preposition "about".It is shown that the student writer encountered a problem with the unnecessary insertion of a word.This error results from L1 lexical interference when the learner employs a direct translation from Thai (Keaw Kub in Thai) to English (about).It can be assumed from this error that it is caused from the direct translation of Thai collocation into English because it sounds correct.
However, the sources of errors committed by EFL writer are complex and some of them don't reflect an isolated factor.When taking into account intralingual error, this unnecessary insertion "about" may result from false analogy (James, 1998).This is because some writers may learn that it is correct when the word "about" is collocated with the word "talk" and "think" to form the collocations "talk about" and "think about".Consequently, it may be wrongly assumed that the word "describe" also needs this preposition.This unnecessary insertion is also found in the word "discuss".

L1 Syntactic Interference
Apart from lexical error, it is also common for Thai student writers to construct English sentences based on direct translation from Thai into English sentences.Subsequently, this L1 syntactic interference reflects common grammar errors, especially regarding subject-verb agreement, verb-tense, passive voice, relative clause, expletive structure and word order.This is because subject-verb agreement is not found in Thai sentential concept, that of specific boundary of Thai sentence is not obvious (Thep-Ackrapong, 2006) and word order in Thai structure is considerably different from that of English.This coincides with Pongpairoj (2002), who addressed the three aspects of Thai syntactic interference in English writing.These aspects are sentence construction, sentence boundary and word structure.Bennui (2008) also examines word order of Thai structure, tense, subject-verb agreement, the infinitive, the verb 'have', prepositions and noun determiners.He points out that the word order of Thai structure in the students' English sentences is caused from "insufficient knowledge of similarities and differences between Thai and English grammatical structure." In regard to L1 syntactic interference, this paper provides some evidence to confirm the syntactic errors caused by L1 interference based on Pongpairoj (2002).The following represents an example error found in Thai student writing.
 Have many trees in the university.(  There are) This example shows that the writer failed to construct an expletive sentence structure (there + verb be).As a result, the sentence "Have many trees in the university" is found in student writing instead of saying "There are many trees in the university".
I like to go out with my friends, but I don't like to have alcohol  it is not good for health.(  because) The second example reflects the sentence boundary error.It exhibits a run-on sentence error in which the independent clause, "it is not good for health" is joined with the preceding sentence without an appropriate punctuation or conjunction.As influenced by L1 interference, a run on sentence can be short, such as the sentence found in a student writing "Someone danced someone sang".In this case there are two independent clauses: two subjects combined with two intransitive verbs.
Apart from sentence construction and sentence boundary, James (1998) proposes errors caused by misordering, which is one of the most common errors found in EFL writing.In regard to this error, misordering is a failure to arrange words in a sentence in the right order based on word-order regulation in English, such as in the following.
He is a  fat boy and friendly.(  friendly, fat boy ) The example coincides with the previous studies and confirm that L1 syntactic interference in English writing by Thai students is commonly found in sentence structure, sentence boundary and word order which reflect the learners relying on carrying out 'word-for-word translation of native language surface structures' (Dulay, Burt and Krashen, 1982: p.163).

L1 Discourse Interference
As specific differences in rhetorical organization have been examined for many non-English languages, Kaplan (1966) also proposes the notion of contrastive rhetoric on written discourse influenced by oral, culture and social value.As influenced by L1 acquisition, studies of non-native English writing indicated that many students use writing conventions more differently than native-speakers do.McDaniel (1994) proposed that many Thai student writers do not use paragraph structure in their writing.Sometimes the writers don't build up a new paragraph for the additional idea created.It is generally accepted that the sources of writing errors made by L2 learners are various.Based on overall patterns of errors found in Thai EFL students' written products (Thep-Ackraraphong, 2006), it is proposed that these deviate forms of writing can be found in both the rhetorical and typological differences between the L1 learners and L2 learners.It is revealed that for rhetorical pattern, Asian writers seem to have a general topic which is "loosely" (p.95) supported in their writings.Also, the real purpose is often found at the end of the piece.This feature contrasts with English-speaking readers who have a different expectation from writers.They expect to find a coherent text in which each supporting sentence directly supports the topic sentence or controlling idea.This coincides with Sattayatham and RatanapinyowongIn (2008).It is found in students' paragraph writing that most students do not present "a reasonable connection or relation" (p.30) between ideas in their paragraphs which cause incoherence.These student writers cannot create connected thought and do not tie prose together and make the words and sentences in their writing unified and comprehensible for the reader.Consequently, their paragraphs are considerably short and unclear.
Some writing problems at discourse level in Thai context can be found in paragraphs which are disunified because the topic sentence, which contains the topic and controlling idea, are often unclear and sometimes appear at the end of the paragraph.As a result, supporting sentences loosely support the topic sentence.However, when compared with the concept of discourse rhetoric based on the growing evidence that different cultures and language communities lead to different conventions and expectations about maximizing rhetorical effectiveness, discourse error found in some EFL writings seem to be open to question.Based on Austin (1962 cited in James, 1998), he is not certain to define this difference as error, but addresses this phenomenon as "infelicity" (p.163).It can be seen that the deviance of writing output of L2 learners is not always wrong, but it is different from the standard of the target language.
It can be seen that interlingual errors are normally found in EFL writing.This is because when writing in the target language, the writers rely on their native language structures to produce their written tasks.As the structures of L1 and L2 have differences, there is a relatively high frequency of errors occurring in the target language, therefore, indicating an interference of the native language on the lexis, syntax and discourse of the target language.

Review of Target Language Causes: Intralingual Interference
This section provides a theoretical review on learning strategy-based error which can result from intralingual errors in EFL writing.This error can be defined as the deviate form of language caused by conflicting information of the target language.Unlike those interlingual errors, which are traced to first language transfer, Scovel (2001) identifies intralingual errors as stating, "…the confusion a language learner experiences when confronting patterns within the structure of a newly acquired language, irrespective of how the target language patterns might contrast with the learner's mother tongue" (Scovel, 2001: p. 51).
This can be noted that intralingual errors are not related to the first language transfer, but contributed by the target language itself.Building on the foundation of the source of error mentioned above, the following discusses the learning strategy-based error which comprises of seven categories; false analogy, misanalysis, incomplete rule application, exploiting redundancy, overlooking cooccurrence restrictions, hypercor-rection (monitor over use) and overgeneralization, or system-simplification.

False Analogy
False analogy reflects errors committed by the writers' not fully understanding a distinction in the target language.This strategy leading to errors coincides with cross-association (George, 1972cited in James, 1998).The writers mistakenly assume the rules in L2 from their known information.The followings illustrate examples of this type of error found in student writing.
My father used to feed many gooses  in the back of the house.(  geese) Childs  in the village like to play with me.(  children) It can be seen from the above examples that the writers have acquired knowledge of adding the noun ending 's' for plural nouns.Consequently, the words goose is pluralized by adding 's' (instead of geese) and the word child is pluralized by adding 's'(instead of children) because the writers may assume that these words were in plural form, so they need to be added the noun ending 's'.

Misanalysis
According to James (1998), this error type is caused from the wrong concept of a particular rule in the target language.For Thai student writers, it is possible that they formed a hypothesis of a TL item and put it into their writing.The examples of these errors are given below.
Harry Potter is my favorite who  has beautiful pictures and exciting scene.
From this example it seems that the writer expresses his/her feeling of the movie by stating the pictures and the scene.The writer misanalyzes that the title of the novel is a boy, so the relative pronoun, 'who' is used to refer to that boy.
I have two pets.Its  is  a dog and a cat.(  They  are) This example is often found in Thai student writing.The writer may hypothesize that since the pronoun 'it' is used to refer to animals and things as a noun, subsequently, the noun ending 's' is also added here to pluralize the pronoun.

Incomplete Rule Application
According to Richards (1971), this sort of error occurs when the deviant structure "represents the degree of the development of the rules required to produce acceptable utterances" (p.15).James (1998) also states that it is opposite to overgeneralization and exemplifies this deviancy of subject and verb 'be' found in the sentence, "Nobody knew where  was Barbie" (* Barbie was).This error results from the writer using incomplete rule of interrogative information.The writer applied a wh-word, 'where', but failed to invert the subject 'Barbie' and the verb 'was' to form a complete declarative statement.This error type is also found in Thai student writing as follows.

Exploiting Redundancy
Redundancy refers to the way the learner employs words or phrases which add nothing to the overall meaning of the sentence.Those unnecessary repetitions should be eliminated because they do not improve writing, but add nothing to what has already been expressed.As the concern in this paper aims to provide some examples of the redundancy in EFL writing, the following illustrates three sorts of redundancies.

Word
My mother and I am very happy to get a *free gift from the department store during New Year Festival.
There are seven steps to use ATM *machine.
As shown above, the word "free" is employed because the writer may assume that it can provide more details for the word gift, as an item that is free of charge or without payment.In fact the word "gift" already refers to things that people give to others on a special occasion or to say thank you.However, this paper does not consider the words "free gift" an error because they are acceptable in standard English as exemplified in Oxford Advanced Learner 's Dictionary (2005).This paper, thus only reflects this needless repetition.Likewise it is also found in the word "machine".Even though the word "ATM" stands for Automatic/ Automated Teller Machine, the writer relies on this abbreviation and uses it to modify the word "machine" which is considered redundant.This case is also found in the words UP university (University of Phayao), HIV virus, ICU unit, etc.

Qualifier
Pang is a *very perfect girl because she is beautiful and intelligent.
We moved to *this here since 2004.
From the first example, it is found that the writer adds a qualifier "very", which is unnecessary to the sense of the word "perfect".According Oxford Advanced Learner's Dictionary (2005), this word is clearly expressed by itself as the state of having everything that is necessary, being excellent or being completely correct.Therefore, there is no need to use the obvious qualifier "very" to modify the word which completes in itself like the word "perfect".Also, in the second example, the writer emphasizes the place "here" by using the word "this", which is unnecessary because the writer tends to express the distance of a particular place that is very close, but either "this" or "here" suffices in the sentence.My friends and I cannot remember all the *past *history of this old palace.
There are unnecessary repetitions of the words "repeat", "again", "past", "history", and the phrase "All the time" and the word "always".The writers decorate their sentences with unnecessary words and phrases of emphasis, though without them, the sentence is equally capable of stressing the meaning.

Overlooking Cooccurrence Restrictions
This error is caused by failing to observe the restrictions of L2 existing structure.Based on James (1998), the example of this error type is addressed in the sentence "I would enjoy to learn".This is considered an error from the overlooking cooccurrence restrictions because the word "enjoy" cooccurs a gerundial complement.The following error is found in a Thai student writing.I am willing to *meeting with all my old friends.(*meet) The example above demonstrates the ignorance of the rule of "infinitive", in which the word "to" needs to be placed before the bare form of the verb.This sort of error is frequently found among EFL writers when that of linguistic element doesn't occur together.The student's explanation for this error is that he is too focused on the familiar word "meeting" and fails to see the relationship between the words "willing to" and "meeting".

Hypercorrection (Monitor Over Use)
The term hypercorrection refers to the writer's over-indulgence of their writing output.This results from the writer's consistency in applying his/her known rule to other information.The following illustrates the error type.
I am a second  years English major student.(  year) Singing English song makes him  improves the language.(  improve) From the first example, the writer may wrongly assume that the phrase 'second year' should be in a plural noun, therefore it is needed to put the noun ending 's' to indicate plural form.Also as shown in the second example, the writer seem to be confused with the rule of adding 's' for the agreement on subject-verb from the word 'him' as a third person singular and the verb 'improves'.

Overgeneralization, or System-Simplification
This error type is found when the writer learns a rule or pattern in the target language, he/ she then, assumes that the rule or pattern operates without exception (Scovel, 2001).In other words, this error can be made when the learner creates one deviant structure in place of two regular structures.Once the writer learns a set of rule, he/she overuses one form in the set and underuses the other.The following provides a clear picture of this strategy that leads to writing errors.
He speaks very  good and I understand him.(  well) I have so  much friends in the university.(  many) As mentioned above, the writer applies the word "good" instead of the word "well" and also uses the word "much" instead of the word "many".These errors seem to result from their confusing of the two related words as well as their over-indulgence of one form in the set and rarely used the other.This error can be found in sets of words which are rather confusing: few, a few, none/neither, other/ another, etc.
Certainly, errors may be caused differently and be complex in which it can be overlapped and sometimes doesn't belong to a clear-cut category.What is certain is that L1 interference and limited linguistic knowledge are likely to be crucial factors in the students' successful acquisition of writing skills in their L2.The students who commit interlingual errors may have their L1 interference when writing in English and they need to improve their grammatical competence, vocabulary and the language system-and discourse competence-genre and rhetorical patterns- (Hyland, 2003).For intralingual errors, the student errors seem to be caused from the limited linguistic knowledge, for instance, in grammar rules which are confusing for student writers.It can be noted that although interlingual and intralingual errors are apparent among EFL student writing, it is necessary for teachers to recognize that these errors may be evidence of their second language acquisition and understandings.

Pedagogical Implication for EFL Context
It is clearly seen that errors are one of the inevitable parts of EFL writing, in which of course, there are many influences over EFL writers when writing in the target language.One of these is the influence by the mother tongue language of the learners and as a result causes interlingual error.On the other hand, frequent errors also result from the process of acquiring the target language called intralingual error which is convincing that the first language transfer is not the only major factor of language error However, both sorts of errors can provide us with a picture of the linguistic development of a learner and may give us indications as to the learning process (Corder, 1974).
The existence of errors has been subject to all language-teaching theories as they represent an important aspect of second language acquisition.The followings provide some pedagogical implications for writing teachers, educators, as well as material developers.
The first implication for language teachers is to seek for the benefit of errors.Based on theoretical aspect, writing teachers can utilize interlingual and intralingual errors as an indicator of how far towards the goal learners have progressed and what remains for them to acquire (Corder, 1981).In other word, errors are a means of feedback for the writing teachers reflecting how effective they are in their pedagogical methodology.Additionally, teachers can research their student errors to find out the flaws that need further attention.Writing teachers therefore should be able to not only detect and describe the errors from a linguistic aspect, but also understand the psychological reasons for their occurrences.Thus, the diagnoses and treatment of errors is one of the fundamental skills of the teacher (Erdogan, 2005).
The second implication emphasizes on the students' error awareness.Errors found in EFL student writers are unique based on their "bilingual, bicultural and biliterate experiences" (Hyland, 2003: p. 50) and they can impede writing accuracy.Thus, writing teachers should educate students about errors and the principles of second language acquisition.One pedagogic practice is to raise students' awareness of their errors.Teachers should assist students to become more aware of them by establishing "a comprehensive taxonomy of the learners' errors" (Husada, 2007: 103) and their sources, i.e., interlingual and intralingual errors.This awareness raising can help students avoid errors.Once the students commit the errors, they can be pointed out to correct.As a result, the correcting error can be done "if there is some understanding of why the error occurred" (Nation and Newton, 2001 cited in Mungungu, 2010: 141).Furthermore, students should learn that errors are a natural part of language acquisition which needs time, effort and patience to overcome (Ferris, 2002).
Although errors tend to be viewed as a result of inadequacy of teaching and learning, it is generally accepted that it can be used as a necessary tool for language teachers to improve their teaching methods.Teachers can develop associated teaching methodology for students to avoid fossilization of their errors in some practical ways.
Firstly, they can prepare supplementary grammar instruction through inductive method and remedial exercises through reading passages which contain the existing structure the students are acquiring.It is suggested to use brief lessons, rather than extensive grammar presentations.The lessons should be based on the students' need, some complicated rules of the language, or untreatable errors selected from the students' frequent errors.
Secondly, when teachers give a response to student errors with either explicit (e.g., direct correction or corrective feedback) or implicit corrections (codes, underlines, symbols, comments in the margin), they should provide the students strategy training in utilizing the teacher response.This can be obvious, for example when receiving code feedback from the teacher, the students should be shown some guidelines of error codes which are not confusing.Then the students can edit their errors by themselves.
Thirdly, the students should be trained to work on their errors through peer and self editing activities in which they have opportunities to track their errors themselves or collaboratively.As a result, they can develop their independent editing skills.Based on these autonomous learning activities, it is recommended to support the students with effective materials and workshop so that the students understand the purpose and the benefit of the activities.
It can be noted that clearly, these suggested issues for pedagogical option are heavily influenced by instructors.Not only do they have to develop pedagogical options, materials, and designed activities, but they also need to have solid linguistic knowledge as well as analysis skills themselves.Therefore, when applying associated teaching methods, the teachers are able to train and guide their students to apply the right strategies to become better language users.As already mentioned, even though errors are considerably undesirable in EFL writing, they may provide some usefulness.Educating the students on the sources of errors can help them realize that although errors are not viewed positively and sometimes obstruct communication, they can facilitate foreign language learning.Errors also play a crucial role in training teachers what needs to be taught, helping them identify and classify learners' errors as well as helping students understand the process to acquire the target language.Thus, it is seen that EFL writer errors can be valued as evidence of how language is learned and the strategies or procedures the learners are employing in language learning.

Conclusion
In this paper, it can be seen that errors found in Thai student writing are mainly influenced by both interlingual and intralingual causes.The theoretical framework of error sources is reviewed.Interlingual errors, lexical errors, syntactic errors and discourse errors are reviewed in terms of first language interference.As for intralingual errors, it is also reviewed in terms of language strategy-based errors (James, 1998) consisting of false analogy, misanalysis, incomplete rule application, exploiting redundancy, overlooking cooccurrence restrictions, hypercorrection (monitor over use) and overgeneralization, or system-simplification.
It is clearly seen that writing errors are assumed as being not only a result of the first language interference habits to the learning of L2, but also inadequate acquisition of the target language.From the first source, interlingual error, it is not regarded as "the persistence of old habits, but rather as signs that the learner is internalizing and investigating the system of the new language" (Erdogan, 2005: p. 265).This is because writers rely on the structures of their own native language and transfer those structures to produce their written language.Unfortunately, they overlook some restrictions of the language transfer process.Also, as the structures of their L1 and L2 have significant differences, a high frequency of errors in the target language occur, especially the errors caused by interference of the native language on the lexis, syntax and discourse.
For the intralingual interference, it is obvious that errors are caused by the influence of the target language than language transfer.Some specific rules in the target language may be rather confusing and may have some exceptions in which the writers need to understand, memorize and practice in order to acquire them.It is true in Thai context that the writer can understand the meaning of the reading passage but fail to grasp the vocabulary and grammar rule as well as spelling of the target language when writing.
However, these common difficulties in language learning can point out some aspects for language teachers.Writing errors can reflect strategies that language learners use and indicate the process of acquiring the target language.Consequently, these would provide language teachers practical aspects in order to develop methodology as well as materials for remedial teaching.

I
didn't visit any place during summer, nor  I reviewed the lesson.(  did I review) At that time I didn't know what  should I say to him.(  I should say) it *again.*All the time I have been here, I *always miss my family.