This study attempts to make semantic and syntactic analyses of Turkish verbs. It also has rich implications for lexical studies and machine translation. It is intended to analyze verb-argument structures in Turkish in terms of thematic roles and grammatical relations; to find out correlations between the two domains, and then to observe how the findings can shed light on certain aspects of Turkish Grammar more satisfactorily. First the theoretical bases of the semantic analyses are provided. Then Turkish verbs are classified into distinct categories according to thematic roles and grammatical relations undertaken. These analyses provide us with a substantial comprehension of the behaviors of arguments during voice alterations and verbal derivations. Turkish verbs are also investigated in terms of morphological, semantic and syntactic aspects and behaviors of arguments, as they go through voice alterations. Finally certain generalizations concerning productivity, changes, and constraints of voice constructions are worked out. The book should be useful for those studying Turkish language in terms of thematic roles and grammatical relations.