Collocational processing in typologically different languages, English and Turkish::Evidence from corpora and psycholinguistic experimentation

Unlike the traditional words-and-rules approach to language processing (Pinker, 1999), usage-based models of language have emphasised the role of multi-word sequences (Christiansen & Chater, 2016b; Ellis, 2002). Various psycholinguistic experiments have demonstrated that multi-word sequences (MWS) are processed quantitatively faster than novel phrases by both L1 and L2 speakers (e.g. Arnon & Snider, 2010; Wolter & Yamashita, 2018). Collocations, a specific type of MWS, hold a prominent position in psycholinguistics, corpus linguistics and language pedagogy research. (Gablasova, Brezina, McEnery, 2017a). In this dissertation, I explored the processing of adjective-noun collocations in Turkish and English by L1 speakers of these languages through a corpus-based study and psycholinguistic experiments. Turkish is an agglutinating language with a rich morphology, it is therefore valid to ask if agglutinating structure of Turkish affects collocational processing in L1 Turkish and whether the same factors affect the processing of collocations in English and Turkish. In addition, this study looked at L1 and L2 processing of collocations in English. This thesis firstly has investigated the frequency counts and associations statistics of English and Turkish adjective-noun collocations through a corpus-based analysis of general reference corpora of English and Turkish. The corpus study showed that unlemmatised collocations, which does not take into account the inflected forms of the collocations, have similar mean frequency and association counts in the both languages. This suggests that the base forms – uninflected forms of the collocations in English and Turkish do not appear to have notably different frequency and association counts from each other. To test the effect of agglutinating structure of Turkish on the collocability of adjectives and nouns, the lemmatised forms of the collocations in the both languages were examined. In other words, collocations in the two languages were lemmatised. The lemmatisation brings the benefit of including the frequency counts of both the base and inflected forms of the collocations. The findings indicated that the vast majority (%75) of the lemmatised Turkish adjective-noun combinations occur at a higher-frequency than their English equivalents. In addition, agglutinating structure of Turkish appears to increase adjective-noun collocations’ association scores in the both frequency bands since the vast majority of Turkish collocations reach higher scores of collocational strengths than their unlemmatised forms. After the corpus study, I designed psycholinguistic experiments to explore the sensitivity of speakers of these languages to the frequency of adjectives, nouns and whole collocations in acceptability judgment tasks in English and Turkish. Mixed-effects regression modelling revealed that collocations which have similar collocational frequency and association scores are processed at comparable speeds in English and Turkish by L1 speakers of these languages. That is to say, both Turkish and English speakers are sensitive to the collocation frequency counts. This finding is in line with many previous empirical studies that language users process MWS quantitively faster than control phrases (e.g. Arnon & Snider, 2010; McDonald & Shillcock, 2003; Vilkaite, 2016). However, lemmatised collocation frequency counts affected the processing of Turkish and English collocations differently, and Turkish speakers appeared to attend to word-level frequency counts of collocations to a lesser extent than English speakers. These findings suggest that different mechanisms underlie L1 processing of English and Turkish collocations. The present study also looked at the sensitivity of L1 and L2 advanced speakers to the frequency of adjectives, nouns and whole collocations in English. Mixed-effects regression modelling revealed that L2 advanced speakers are sensitive to the collocation frequency counts like L1 English speakers because as the collocation frequency counts increased, L1 Turkish-English L2 speakers responded to the collocations in English more quickly, as L1 English speakers did. The results indicated that both groups showed sensitivity to noun frequency counts, and L2 English advanced speakers did not appear to rely on the noun frequency scores more heavily than the L1 English group while processing adjective-noun collocations. These findings are in conflict with the claims that L2 speakers process MWS differently than L1 speakers (Wray, 2002).