The Simple Past Tense in Turkish grammar, also known as the Definite Past Tense, describes the actions that occurred in the past and are certain. This tense is typically identified by the verb ending in “-di”, “-dı”, “-du”, “-dü”, “-ti”, “-tı”, “-tu” or “-tü”. Turkish conjugation of the simple past tense varies based on the vowel harmony rules of the language. Each verb is conjugated to match the subject of the sentence.