I admit to being almost entirely ignorant of the history of Israel, but I am aware that many of the people who lived there in the earlier years were European Jews. And because they came from a variety of nations beforehand, and therefore speak different languages, how did these people communicate? Was Hebrew something most already knew in a great degree of fluency before they emigrated?
The European Jews generally spoke Yiddish. There was a debate in Zionism in the early years whether people should speak Yiddish or Hebrew. The negative side to Yiddish was that it was consider the language of the diaspora, of the ghetto. The negative to Hebrew was that it was almost a dead language and were missing a lot of words necessary for normal conversation.