Thammasat University, Thailand (firstname.lastname@example.org)
The split infinitive in English has been controversial for over a century. Whilst a prescriptive grammar rule forbids infinitive splitting, it seems that modern grammar academics, as well as users, accept and allow for its occurrence. The approval of split-infinitive structure has also been clearly substantiated by plenty of convincing linguistic evidence: real data from native-speaker corpora confirms its existence in different varieties of English. The present study, using the data collected from Thai Learner English Corpus (TLEC), shows that professional English learners evidently produce a greater number of split infinitives than intermediate learners, whose proficiency level is lower. According to a comparative study of the two learner corpora, the higher the proficiency level of the learner, the greater of the production of the split infinitives, and low-proficiency learners seem to use split infinitives in a more specific context.
Keywords: split infinitive; learners’ proficiency; learner corpora; corpus-based data; corpus linguistics