how do you predict a opponents moves?

I think the easiest way to predict moves is if they're forced moves, like putting their king in check. However this question can probably be answered much better from someone with a higher rating than me.

Imo, the short answer is “Play the board, not the player.” But, sometimes you can see signs they are trying to set up for something. Are they trying to move their pieces closer to your king? They are going in for a mating attack. Are they trying to trade off all the pieces? Maybe they want an endgame or more space or to fend off an attack. If their moves seem kind of random, maybe they are confused or don’t know what to do. But no matter who you are playing, after they move, ask yourself what they are trying to do. Mostly we can only make educated guesses about what our opponent is going to play next. Experience will make you better at it, but for now, it might help to think about what is objectively best or what you would do if you were playing their side.

I agree with Toviya, you don't really guess or predict opponent moves, but rather see what is their greatest attacks and you try to eliminate them while also trying to create threats of your own

I look at threats, forced moves, what I would do.

It's also important to try/attempt to predict your opponent's best move; too many times, beginners see only the moves that benefit them or that are not their opponent's best moves. As a result they wind up in trouble, with loss of space, defending rather than attacking and even more important down on force. Try and predict their best moves!

I have a complete blog on this: Prophylaxis in Chess

Hope it helps!

Pretty good advice there from toviya, I always ask my self if i was them what would i play next. More so in the middle game. With openings, there are moves your going to expect to see as you climb "theory" and when someone plays a strange move in the opening your going to notice it eventually a nd will know thats not how they should play the position and theres usually a way to punish sideline moves. So i guess its experiance. If there not threating anything with there last move i just improve my peices, play prophalatic moves, take more space etc. If they fiachetto a bishop...make it stare into a pawn chain, there are suttle ways to controll parts of the game. If your playing higher rated people in school, look up some opening traps an gambits so you dont get tricked.

You don’t/can’t predict moves unless they are forced, like a checkmate. You just look for the best replies for your opponent. If they don’t play that move, it should be easy to refute. For example:

1...e5? HA! But as you can see, that move is garbage.

Look at the board, what is en prise (unprotected), checks, captures and threats.

Unless you're playing bullet, you don't need to predict moves at all