Remember at the end of an interview when an employer asks, "do you have any questions for me?". Well, keep in mind that they want you to ask questions. We typically say fire away and you should. But there are a few questions you should never ask in a job interview.
What does your company do?
By asking this, you're just admitting you haven't done the proper research on the company. A quick internet search will save you a lot of time and embarrassment. You should go in with at least an idea of what the company does.
How long will I have to work before I can ask for a raise?
The employer wants an employee who is passionate about their job, not just the money that comes with it. A job interview is not the best place to be all about the Benjamins. Your focus should be on getting the position so steer clear of asking about time off too.
What exactly will you look for in the background check?
This question will make the interviewer worry that you have something to hide. You don't want to come across like you have a lot of skeletons in your closet (we mean that figuratively of course).
How soon will I be promoted?
While you do want to show the employer you're ambitious and want to grow within the company, this question gives off the impression that you won't be happy in this current position. You have to work your way up to climb the corporate ladder.