It's been over a year since I wrote my list of things learned from horror movies. At this time I would like to revisit this idea, but with a twist. I now give you things to never say in a horror movie scenario, lest they be the last words you ever utter.
"I'll be right back." Whoever says this never comes back. Not alive anyway. Undead, living dead, but never in their original state.
"Did you hear that? Someone should go check it out." And goodbye inquisitive idiot.
"Is anyone there?" Of course someone or something is there. But they usually won't answer verbally.
"Who's there?" If you've seen Scream, you know this one. If you haven't seen the movie, just don't ask this question. It doesn't end well.
"It's just (fill in the blank: a dog, an old man, one night, around the corner, a book)." It's never just a dog, a spider, a clown, or the wind. Assume worst case scenario.
"What's in here?" I guarantee you it's nothing you want to know about.
"It can't be him/her!" Sure it can, and it probably is. Cue the next line...
"It's you!" at which point the speaker meets his or her end for having figured out who is responsible for killing the everyone, creating the monster, releasing the monster, and so on and so forth.
"Is that the best you can do?" Of course not. If someone is still alive to utter such lines, it's proof that the antagonist (be it monster, alien, vampire, werewolf, or disturbed truck driver) can in fact do better. Don't taunt them by challenging their abilities.
"It/he/she is dead." Unlikely. Don't get too close.