Oral and Written Competence of Chinese Foreign Language Learners in Terms of Lexical Chunks

The role of the lexical chunk method in the second language acquisition has gained more and more attention in recent years. The paper briefly introduces the definition and meaning of the lexical chunk method, analyzing the studies on the acquisition of oral and written competence of Chinese foreign language learners in terms of lexical chunks.

Vocabulary is central to language acquisition and the ability to understand chunk language successfully is a key to an understanding of how language works (Lewis 1997).Lexical chunk is regarded as a significant part of the second language learning by more and more linguists.As a result, more and more research on lexical chunks in second language acquisition has been carried out in China.
As the study perspectives and emphases are different, researchers use various terms such as patterned chunks, prefabricated chunks, lexical phrases, routinized expressions, lexical bundle, and ready-make complex units (Li Hongye, 2004;Yan Weihua, 2003).The concept prefabricated phrase was first proposed by Becker in 1975.It was Michael Lewis who first used the term chunk in 1993, and established the basis for lexical chunk at the same time.According to Lewis (1997), chunk "is based on the idea that an important part of language acquisition is the ability to comprehend and produce lexical phrases as unanalyzed wholes, or "chunks", and that these chunks become the raw data by which learners perceive patterns of language traditionally thought of as grammar."Some Chinese researchers also give their viewpoints.Duan Shiping defines lexical chunks as prefabricated multi-word units stored in brain in integral form which can be extracted to use (Duan Shiping, 2008).Wei Naixing believes that prefabricated chunk is a language structure with both lexical and grammatical characteristics, usually multi-word units that have linguistic function with specific characteristics of discourse function (Wei Naixing, 2007).
The classification of lexical chunk differs from one researcher to another accordingly.In their description of lexicalized stems, which are lexical chunks in essence, Pawley and Snyder divide lexicalized stems into four groups: poly-words, institutionalized expressions, phrasal constraints and sentence builders.Second language prefabricated chunks are divided into four categories in terms of their structures (Nattinger & DeCarrico 1992): poly-words, institutionalized expressions, phrasal constraints, and sentence builders.

Lexical chunk and L2 oral competence
Some Chinese researchers have studied the significance of learning lexical chunks in the improvement of oral communication of second language learners.There are studies on college English teaching, oral fluency of a second language and so on.Generally speaking, current studies are guided by two directions: exploring the oral ability in terms of lexical chunks and investigating the correlation between oral ability and the use of lexical chunks.
Oral communication can be studied from the perspective of communicative performance and communicative competence (Jiang Yuhong, 2007).An analysis of the differences between English native speakers and learners in their use of chunks has revealed that learners use much more types of recurrent sequences which are closely tied with the expression of propositional meaning, but much fewer types of recurrent sequences which basically perform pragmatic functions (Wei Naixing, 2007).Some research reveals that, during oral English tests students' ability of using lexical chunks in the process of retelling stories in English is limited and at the same time lexical chunks are used much less when they make impromptu speeches.Most of the phrases and lexical chunks have simple structures and clear meanings.The structures of words with lower frequency counts are different from equivalents in Chinese.Their mother language interferes with and obstructs the learning and the use of lexical chunks.
The ability of employing lexical chunks is closely relevant to the oral English level; higher-level students usually can employ more lexical chunks (Ding Yanren, 2005).It is obvious that Chinese students overuse some common interactive chunks (I think, for example).The distinguishing feature of Chinese college students' oral English is overusing of first person singular.The overusing of the cognate chunk of I think accounts for 64%of all interactive chunks in College Learners Spoken English Corpus, which can be called "I perspective" in conversations (Xu Jiajin, 2007).
According to some research, no significant difference was found in the use of lexical chunks for students at different levels of proficiency.Although no noticeable difference was found between groups of low proficiency and high proficiency, noticeable difference was found in the amount of lexical chunks and sentence patterns used between groups of low proficiency and middle proficiency, and also between groups of low proficiency and high proficiency (Liu Jiaying, 2006).
Thus, the oral English of Chinese learners shows not only similar lexical chunk features to spoken English of native speakers but also unique characteristics of its own reflected by all those research results.The knowledge of lexical chunks plays an essential role in English knowledge structure.What could not be denied is that these results still reflect the mastery and application of lexical chunks to a certain degree.Lexical chunks could be used as an important indicator of different oral English proficiency levels for second language or foreign language learners.Problems in the use of lexical chunks may have negative effects on efficiency, appropriateness and politeness of communication with native speakers.In oral English, functions of language which are endowed with typical significance such as consent, praise, surprise, suggestions, advice, anger and so on, is expressed by a number of specific language forms.These forms of expression with the conventional features come under the category of "lexical chunk" (Liu Jiaying, 2006).Most research showed that the use of lexical chunks is positively correlated with oral competence, proficiency and performance of second language learners.The use of lexical chunks and framework of sentences can significantly improve the oral fluency in a second language.It is found that the knowledge of lexical chunks possesses stronger predictive validity of oral competence than that of grammar.The use of lexical chunks in actual communication can reduce the effect of negative transfer of mother tongue, and can help to narrow the gap between learners and native speakers in diction and discourse output (Jiang Yi, 2007).
These research results hold the same views as Widows, maintaining that learning lexical chunks is more important than learning grammar, and the use of grammar is just to ensure that lexical chunks can meet the grammatical and contextual needs.Some studies indicate that the number of lexical chunks used in oral English does not increase significantly as second language level increases, which suggest that the number of chunks in oral performance can not be a measure of second language learners' language level, and the development of their fluent oral output is not a continual process.
Lexical chunk learning promote the oral proficiency of English learners not only as viewed from grammatical competence, but also in terms of the external communicative performance, by improving processing speed and expressive accuracy, and relieving learners' time pressure and psychological pressure in real-time interaction (Jiang Yuhong, 2007).

Lexical chunk and L2 written competence
Based on lexical chunk, some Chinese researchers conduct investigations into its effects on written ability of second language learners.The subjects consisted of engineering students, English majors, vocational college students and non-English majors, and covered some types of writing such as L2 timed writing and business writing.
There are some distinctive features among Chinese second language learners in terms of lexical chunks that are used in composition.First, Chinese students' productive notional words are limited, while de-lexicalized verbs are less used in students' writing.Second, three-word chunks come first in number in COLEC, while six-word chunks the last.Learners are found to use 4 times as many lexical bundles as the native speakers do, but most of them are topic-related, while the native speakers use more functional bundles.
Third, the Chinese learners use a special type of stance bundle, "third person plural", while the native speakers use impersonal stance bundles instead.And finally, Chinese learners use more "verb phrases with active verbs" and "noun plus verb patterns", while native speakers use more "noun plus preposition patterns", bundles with past-tense verbs, NP+PP bundles and bundles with appositive clause or attributive clause chunks have very low frequency in the L2 timed essays (Pang Ping, 2009;Liu Xianghong, 2009;Liu Xiaoling, 2009;Ma Guanghui, 2009).
Most studies suggest that the ability of using lexical chunks in compositions of Chinese English learners is unsatisfactory in that lexical chunks account for a very small proportion in writing.In most cases, when writing in English, they mainly use words to form a sentence, which makes the usage of language nonstandard and nonnative-like.What the students can use correctly and exactly are a few simple phrases and short sentences.But another study show that Chinese EFL learners have a strong belief in effects of chunks on vocabulary acquisition and high frequency of such preferences is practiced and high-achievers pay more attention to chunks in learning and memorizing new vocabulary than low-achievers (Yan Weihua, 2008).In other words, the ability of using chunks is closely connected with language proficiency, and can be viewed as an important marker or a significant part of the English level.This finding happens to agree completely with the previous studies (Diao Linlin, 2004).The number of lexical chunks that are employed has some explanatory power over both written and oral English levels (Ding Yanren, 2005).
With respect to advanced English learners, in order to promote proficiency and accuracy in writing, they must solve the problem of quick output of language.As proved in Lexical Approach, lexical chunk output is the fundamental way to improve writing ability.The biggest obstacle in composition for many students is that they can not find out nor use the required words and phrases as soon as possible (Yan Weihua, 2008).
Lexical chunk is an important element in the discourse cohesion and coherence.To comprehend and produce discourse is not to learn the isolated words and sentences, but to integrate these prefabricated chunks of languages to form fluent and appropriate expressions (Li Taizhi, 2006;Huang Hongli, 2009).The lexical chunk approach can significantly enhance learners' writing proficiency.But as to the specific indexes of writing quality, including fluency, accuracy, and native-likeness, the lexical approach exerts influence on them to different degrees (Liu Lin, 2009).
From the standpoint that output is helpful in language learning, we should view excessive hepatic output as normal phenomenon in the process of second language learning, and adroitly guide action according to circumstances to assist second language learners to acquire full competence in these lexical chunks by feedback and re-output (Ma Guanghui, 2009).Teachers should try to improve the consciousness and ability of using lexical chunk for students, and chunk teaching benefits L2 learners' productive ability in L2, particularly in the aspects of morphology and syntax (Xi Yan, 2005).

Conclusion
This review reveals that lexical chunks play an important role in the learning of English as a second language and can contribute much to enhance a learner's pragmatic competence.Lexical chunks are helpful for college students to understand the discourse structures and speech rules, and promote their fluency and accuracy in oral and written English.However, the disadvantages of "chunking" should not be ignored if it is acknowledged that chunks are learned as unanalyzed units.Parts of the unit may not be available for creative combinations with other parts (Zhou Junying, 2007).But in view of the fact that there is high correlation between acquisition of chunks and vocabulary and structure performance, both teachers and learners should pay more attention to features and functions of lexical chunks.