The use of prepositions in the ma theses written by the native speakers of English and the Turkish speakers of English in the interdisciplinary departments: A corpus-based study

Corpus-based studies had a long way through the history. However, for a big part of its lifetime, it was declined and kept in the background until technology came up with new advances that support corpus-based research heavily in many terms. The amount of the studies was increased with the development of technology. These studies had various point of views and narrowed their scope of focus down to very specific parts of the language. They attempted to look at different parts of the language by comparing different cultures or contexts, or types of speakers. In the current study, the aim was to focus specifically on prepositions and their natural usage in an acamedic writing environment and compare the frequencies of them in the abstract, the introduction, and the conclusion sections of these texts. The study also tried to investigate which sections used more prepositions and defended possible reasons for doing it. To fulfill the purpose of the study, academic texts were selected as MA theses written between 2008-2018 in the randomly selected interdisciplinary departments, such as Business Administration, History, International Relations, Psychology and Sociology. 50 theses written by the Turkish speakers (TSs) of English, and 50 theses written by the native speakers (NSs) of English were selected. This total of 100 theses formed the corpus data for this particular study. The frequency of the prepositions were analyzed through a software called Keyword In Context, which also provides concordance lists to help the researcher confirm the prepositional nature of the prepositions. Additionally, log-likelihood calculation was applied to find the overuse and underuse values by comparing two types of speakers. The results of the study indicated that the Turkish speakers (TSs) of English had a bigger corpus size. However, TSs showed a significant underuse of the prepositions in the abstract and the introduction sections, and a significant overuse in the conclusion sections when they were compared to the NSs. The possible reasons why specific parts had such results were also discussed. According to the results, it is observed that each section had its own specific reasons related to the nature of the section itself, and the interdisciplinary field of the study. Briefly, the abstract sections used the prepositions in less amount compared to the other sections due to its corpus size, and the most used prepositions were "about" to express the meaning of purpose, "between" to express the meaning of a comparison. The introduction parts had different corpus sizes depending on the interdisciplinary department. For instance, history theses had much bigger corpus size and used high amount of prepositions to express place and time many times while pyschology theses kept the section short and did not use a high population of prepositions. Eventually, for the conclusion part, it was observed that Psychology theses had the biggest corpus size with the most prepositions due to the necessity of giving detailed explanations and making comparisons, while all other sections had a similar population of words as prepositions and corpora size.