Testing Processability Theory In EFL Context

As a notable theory explaining second language(L2)grammatical development trajectories,Pienemann's Processability Theory(PT)addresses this issue from the perspective of learner's language processor.It hypothesizes that,due to the architecture of language processor,learners acquire L2 grammar in a series of universal developmental stages.That is,word/lemma access,category procedure,phrasal procedure,S(entence)-procedure and subordinate clause procedure.Since PT's developmental hierarchy was put forward,a body of research has tested its applicability in typologically different L2s,but the findings are inconsistent with some lending substantial cross-linguistic support for it while still some raising counterevidence to it.Besides the developmental hierarchy,PT also addresses the role of formal instruction in L2 development within its Teachability Hypothsis(TH)which mainly claims two key points:a.Language learners cannot skip the predicted developmental stages through instruction;b.Formal instruction can only be effective if it focuses on the grammatical knowledge of the next stage of the learner's current stage(Pienemann,2015).Previous studies on TH have tested either the first claim or the second claim and their findings are also inconsistent.Basically,this thesis aims to address two issues about PT:further test PT's developmental hierarchy under Chinese EFL(English as a foreign language)context and figure out the effect of formal instruction in L2 grammatical development within PT framework.Study 1 is designed to answer research question 1:Do Chinese EFL learners go through fixed developmental stages as predicted by Pienemann's PT.Seventy-six learners from four different proficiency levels participated in this cross-sectional study and their speech production were analyzed through quantitative distributional analysis,emergence criterion(EC)and implicational scaling.The coefficient of scalability(C of S)is 0.991 for syntax,0.952 for morphology,0.978 for syntax and morphology.The results reveal that Chinese EFL learners' syntactic and morphological development is indeed in line with PT's developmental hierarchyStudy 2 is conducted to answer research question 2:What is the effect of formal instruction targeting at the next+1 stage of the learner's current stage for stage advancement.It followed a traditional pretest-instruction-posttest-interview design and 27 participants from study 1 further participated in this study.They were either at stage 4 or stage 5 in the pretest in terms of question structure.After intensive instructional sessions of stage 6,almost all(except for B4 and B23)the participants advanced to the following stages and nine of them even exhibited stage-skipping,which provides counterevidence to the claims of TH.Overall,this thesis offers cross-linguistic support for PT's developmental hierarchy while presenting counterevidence to its important component,Teachability Hypothesis,urging TH to reconsider its applicability under Chinese EFL context.