who lived in the 11th century, stated that the Oghuz language was the simplest among all Turkic languages.

Swedish turcologist and linguist Lars Johanson notes that Oghuz languages form a clearly discernible and closely related bloc within the Turkic language family as the cultural and political history of the speakers of Oghuz languages has linked them more closely up to the modern age. Western Oghuz languages are highly mutually intelligible