In Nehemiah 13, half the children of mixed marriages spoke the language of which place?

Answer: Ashdod

Jews had married women of Ashdod, Ammon and Moab; half their children spoke the language of Ashdod and could not speak Judah's.

“In those days I also saw Jews who had married women from Ashdod, Ammon, and Moab. Half of their children spoke the language of Ashdod or of the other peoples, but could not speak the language of Judah.”— Nehemiah 13:23-24 (BSB)