Forum:Play trap hole in anticipation?

My roommate and I dug out our old cards about a month ago so we are still relatively new to more competitive play.

Are trap cards that say "when (something happens), (do something else)," like trap hole, able to be activated in anticipation of the trigger event? Can my opponent play trap hole at the beginning of my turn, preventing me from summoning any monsters with more than 1000 ATK?

Sorry if that's a dumb question but I couldn't find an irrefutable answer anywhere. Thanks.