In broad terms, the accents for 4/4 time are loud soft medium soft (or so my piano teacher had me believe), then there's 3/4 which is loud soft soft, and if you want to get really tricky and confuse the issue further, you could look at 6/8 time which usually comes out like a fast waltz time beat because you're changing the base note (4) to an 8th note which of course in musical terms it a shorter beat (in comparison to a 4th note).
eta: I hope I've got that right. It's been a while since I played much classical music and had to think about the time. I'm sure limey can correct me if I'm wrong.