What is the "Jews' language" spoken of in Nehemiah 13:24?

>“And their children spake half in the speech of Ashdod, and could not speak in the Jews’ language, but according to the language of each people.” (Nehemiah 13:24, KJV 1900) 1. What is this Jews' language mentioned in this verse? Is it the Biblical Hebrew language or the Mishnaic Hebrew language or the Aramaic language? 2. What is the speech of Ashdod? 3. What is half speaking? Did they mix both the languages and speak?