clause complexity in applied linguistics research article abstracts by native and non-native english writers: taxis, expansion and projection

halliday’s systemic functional linguistics (sfl) has stood the test of time as a model of text analysis. the present literature contains a plethora of studies that while taking the ‘clause’ as a unit of analysis have put into investigation the metafunctions in research articles of a single field of study or those of various fields in comparison. although ‘clause complex’ is another unit of sf analysis, by far there has been only one study on research articles where it was the unit of analysis (sellami baklouti, 2011). therefore, the purpose of this study was to put into analysis the ‘taxis’, ‘expansion’ and ‘projection’ deployed in applied linguistics research article abstracts (raas) by native (n) and non-native (nn) writers. to this end, 20 applied linguistics raas (10 by n english writers and 10 by nn english writers on the sub-fields of discourse analysis and language assessment) were analyzed according to halliday & matthiessen’s (2013) ‘clause complex’ framework. the results indicated that there is a significant difference in the use of ‘projection’ by ns and nns, while the distribution of ‘taxis’ and ‘expansion’ is the same. the findings also showed what types of ‘taxis’, ‘expansion’ and ‘projection’ were deployed by ns and nns.