A while ago I posted a couple of propositions, but didn’t really explain the difference between them. Here they are
1) Necessarily, God knows at t1 that S will do x at t2.
2) God knows at t1 that, necessarily, S will do x at t2.
The placement of the word “necessarily” makes a difference. By “necessarily,” I mean can’t not be true or must be true. In (1), the necessity is in God’s knowledge of what S will do at t2. God, being omniscient, would necessarily know what S will do. This does not mean that S must do x, though. S could do y instead, and if he did, the proposition would be changed to
(1*) Necessarily, God knows at t1 that S will do y at t2
The necessity is in God’s knowledge of truth, not in S’s action
(2), however, places the necessity in S’s action. S will do x at t2 and there is no possible world that he exists in where he will do anything other than x.