The voice suffixes from Old Turkic to Turkish

In the investigation, firstly, the concept of voice has been argued out and there is a focus on the assortment studies about this subject. In process between old Turkic and Turkish, the verb with voices have been examined in order to ascertain the changes of voices overtime and those which have lost their function has been confirmed. Every verb which has lost its function has been tried to be explained by being compared with its old and new form. In addition to this, the verbs which have been integrated with suffixes ?lAn-, -lAt-, -lAş-, have come under four heading as Orhun, Uygur, Karahanlı and Turkish period.