וּבְנֵיהֶ֗ם חֲצִי֙ מְדַבֵּ֣ר אַשְׁדּוֹדִ֔ית וְאֵינָ֥ם מַכִּירִ֖ים לְדַבֵּ֣ר יְהוּדִ֑ית וְכִלְשׁ֖וֹן עַ֥ם וָעָֽם׃
and their children spoke half in the speech of Ashdod, and could not speak in the Jews’language, but according to the language of each people.
Read midrashic interpretation of Nehemiah 13:24: and classical rabbinic exegesis.