Interviewing for a job is unnerving. Even people who have a lot of self-confidence feel vulnerable to some degree. That's because when you're being judged, every nuance counts.

See also: Tough job interview questions you should ask

While you're keenly focused on putting your best foot forward and asking smart and sometimes tough questions, it's oh-so-easy to say something that could knock you out of the running. When an awkward question slips through your lips, even the smoothest of interviews can go south. Here are some examples of questions you should steer clear of in interviews.

Asking questions during a job interview is important, but some questions are best saved for when you're actually offered the position. — Istockphoto

1. Does my age concern you?

When you're interviewing for a job and you're over 50, you're painfully aware that ageism is alive and well in many workplaces. There's the subtle sense that the hiring manager is seeing your expiration date, rather than your future potential. Or perhaps he or she is not sure you have the stamina and energy to keep up with the pace the position demands.

That said, even if you think age might be an issue, don't ask about it directly, advises Nancy Collamer, a career coach and author of Second-Act Careers. For many reasons, some related to age discrimination law, hitting the age question head on might scare a potential employer off.

"Instead ask a more general question," she suggests, such as: "Do you have any concerns about my capabilities and background that I can clarify?"

2. Will I be working for someone younger than myself?

Employers often sweat that older workers won't feel comfortable reporting to someone younger, and face it, there's a good chance you will have a younger boss. This question will immediately give the impression that you're not up for it, says Elizabeth Craig, a job search strategist at ELCglobal.com. Instead, as you get close to a job offer or at the time of a job offer, ask to meet your potential boss and the team you'll be working with. "This provides the information you were seeking in a positive way," she says.

Try to open yourself up to the possibility of working for and coexisting with someone younger, and highlight ways you've done so successfully in the past. If you are asked how you would feel about having a younger boss, talk about how it was a good experience. For example, you may have mentored someone younger in effective sales techniques, and were in turn mentored in areas that were new to you.

3. Can you tell me about your company's benefits?

This is a genuine job-seeker query, but hold your horses. "It's too early in the process to be talking about this," says Hannah Morgan, a career strategist at CareerSherpa.net. "Many times the hiring manager doesn't know how it works, or even has the scope of expertise to communicate it. You're putting the cart before the horse."

Of course, you want to know how much the company contributes toward health insurance and how much vacation you will get. "For the average job seeker 50-plus, vacation time, for example, is very important," says Morgan. They're at the stage where four weeks of vacation is probably what they've had in the past, and thinking about less is a concern, she says. Plus, the employee out-of-pocket cost of health insurance is increasingly a worry as you get older. You also want to know how fast you can get vested in a 401(k) plan and qualify for matching employer contributions.

But don't ask yet. Instead, Morgan suggests networking with people who currently work there to find out what their experience is. Benefits can vary by department and seniority, but it will give you an idea of what to expect. Save this question for when you are negotiating the offer.

Collamer says you might be able to get benefits information by taking a different approach. "It's fine to ask open-ended questions, such as 'Tell me what you enjoy most about working here,' that might lead to information about the company's benefits, but keep the initial interview focused on job-related questions and save the questions about benefits for subsequent discussions."

Next page: Asking about training could be a real turnoff. »