Turkmen Turkish is included in the eastern branch of Oghuz Turkic dialects. Although it has different features from other Turkish dialects in many aspects, some of its features are also different from other Oghuz Turkish dialects. Another important feature that distinguishes Turkmen Turkish from both other Turkish dialects and Oghuz Turkic dialects is the use of the dative case suffix. When the dative case suffix is added to the words ending with vowels, the y sound is inserted in other Oghuz phrase Turkish dialects such as Turkey Turkish, Azerbaijan Turkish, Gagauz Turkish, while the suffix is added directly without a consonant in the Standard Turkmen Turkish and in the majority of Turkmen dialects. When the first studies on Turkmen Turkish are examined and some dialects with few speakers are examined, it is seen that the y sound is added. In addition, in some of the first studies on Turkmen Turkish, the dative case suffix is provided as +(y)A. In this study, the +(y)A form of the dative case in dialects and in the first grammars has been revealed.

Turkmen Turkish, dative, morpheme, case.