| In recent years,lexical chunk has been long taken as a hot topic in linguistic study.It is well-acknowledged that lexical chunk contributes significantly to language comprehension and expression fluency in that they can be restored in human’s mental lexicon as a whole unit,or remain closely connected to one another in neuro-linguistic system,reducing human’s brain burden on information processing,recognition and retrieval(Corte,2004).As Wary(2002)puts it,second language learners need to get familiar with some common collocations and phrases in the target language before they truly acquire that language.Therefore,lexical chunk competence has been regarded as one of the most important indicators on language learners’ language proficiency(Corte,2004)and a standard that tells an expert writer from a green hand(Hyland,2008a).At the present of time,lexical chunks have been studied by plenty of linguists and scholars both at home and abroad from various perspectives,largely enriching the chunk basis of second language teaching and learning both theoretically and practically.While on the other hand,the majority of these studies are cross-sectional and reach their conclusions basing on the analysis of chunk quantity with comparatively fewer studies focus on chunk quality longitudinally.Paquot & Granger(2012)state that it will be much easier for the language learners to accumulate more chunks than making progress on their chunk application competence.Therefore,considering the present research status and the shortcoming on English majors’ lexical chunk output competence in argumentative writings(Hu et,all state in their research in 2017 that English majors still show a quite low output rate on the target lexicalchunk retrieved from the native speakers’ writings),as well as the peculiarity four-word lexical chunk has(as Cortes puts it in 2004,many of them “hold three-word chunks in their structures”,and “present a wider variety of structures and functions to analyze” than five-word chunks),this thesis takes the argumentative writings in Spoken and Writing English Corpus of Chinese Learners 2.0(2008,Wen et.all)as its research data,studying the characteristics on how Junior and Senior English majors use four-word chunks in their argumentative writings from both aspects of quantity and quality under a longitudinal design,through which the author aims to find out the improvements English majors might achieve on their chunk competence through four academic years’ study,and whether the improvement on chunk quantity indicates the improvement on chunk quality,hoping to offer her own pedagogic implications for English teaching and learning.The following two research questions are concerned in this thesis:1)What are the similarities and differences on the characteristics of the four-word lexical chunks applied in Junior and Senior English Majors’ argumentative writings from the aspects of quantity and quality?2)What are the common misuses in Junior and Senior English majors’ argumentative writings? What are the similarities and differences on how these common misuses are distributed in Junior and Senior English majors’ argumentative writings? And how to avoid and correct these common misuses through pedagogic activities?The research results showed that,firstly,compared with the Junior students,although the Senior English majors made clear improvements on the use of four-word lexical chunks in their argumentative writings by applying more chunks with richer variation,while their chunk accuracy dropped slightly;on the other hand,the two research groups also shared some similarities,as the four-word lexical chunks were obviously unevenly distributed in both Junior and Senior English majors’ argumentative writings with students from both groups underused some of thefour-word lexical chunks,and high-frequently used some of other ones,while the overusing phenomenon did not exist in neither group.Secondly,both Junior and Senior English majors made the following common misuses on four-word chunk in their argumentative writings: errors on agreement(AGRE),errors on collocation(COLL),errors on word class(CLASS),errors on preposition(PREP),independent extrusion(INEX)with AGRE taking the highest proportion,which can be further put into two categories: disagreement between subject and predicate,and disagreement between the singular and plural form.While compared with the Junior group,the Senior group’s error rates on AGRE and COLL were raised,yet these on CLAS,PREP,and INEX were dropped.To help their students to avoid and correct these misuses,English teachers should 1)highlight mother tongue inference and differences between English and Chinese expressions;2)apply the chunk approach and guide students to take lexical chunk as the smallest meaningful unit that can be used independently instead of words;3)remind students to focus not only on chunk forms and meanings but also on the grammatical and pragmatic capacities required for chunk output. |