I believe if there are not much action in game, you can safely assume the opponent is playing defensively. If there are a lot of counter attack breaks from your opponent (not talking about one or two) then it is definitely counter attacking on.

I also think that if your player makes a lot of mistakes/slips, then it's whole pitch pressing especially if it's your defender/mc.

Opponent team having less possession but has more shots then he is either attacking or at normal mentality.

You can be 100% sure.