What do the three witches predict will happen to mecbeth?

That he would be king hereafter. That one was clear. That he would be Thane of Glamis? Not really a prediction, since that had happened in the past and Macbeth knew about it. That he would be Thane of Cawdor? Also not really a prediction, since the King had already named him Thane of Cawdor, which the witches knew but Macbeth didn't. The only thing the witches say in Act I that is about the future is that he will become king. Well, what about Act IV then? You might argue that the predictions in Act IV don't really come from the witches but rather from "their masters", whatever that is supposed to mean. But leaving that aside, the first thing said is "Beware Macduff!". Well, that is no prediction, just a warning. The other two things which are said are both predictions: that Macbeth will not be killed by a man of woman born, and that he will not be defeated until Birnam Wood comes to Dunsinane. These two, and the one about becoming king, are the three predictions made to Macbeth.