The processing of Turkish case suffixes in native language and second language acquisition

Case suffixes are defined as expressing the grammatical functions of the main arguments of a sentence with the help of a morpheme (Spencer & Zwicky, 1998). Case suffixes are mostly used to give information about the arguments roles of the sentence in verb- final and free word order languages such as Turkish, Russian, Basque, Japanese, Finnish, German (Díaz, et al., 2011). Case suffixes are associated with all syntactic, morphological and semantic processes (Frisch & Schlesewsky, 2005). Therefore, this linguistic feature is characterized by a unique degree of multidimensionality. The purpose of this study is to determine how + definite and - definite objects affect the processing cost and to reveal whether there is a processing difference in the authorization of object case and subject case. For this purpose, self-paced reading method was applied. In the first analysis, it is determined that + definite objects are processed more easily than the - definite objects. Possible reasons for this are that definiteness and specificity features of + definite and - definite objects are different, and - definite objects create pseudo incorporation with verb, which creates additional processing costs. In the second analysis, in which subject and object case suffixes are examined, it is seen that processing of the subject case creates more processing cost than processing of the object case. It is thought that, contrary to the authorization of the case suffixes of the object within VP, the authorization of the case suffixes of the subject within TP, furthermore the linear distance between subject and verb, and the involvement of more features in the authorization of the subject may cause this difference.