7 things you should never say in an interview

You dry cleaned your suit. You have a dozen copies of your résumé, just in case. You arrived early -- but not too early. You silenced your cell phone. You made small talk with the receptionist, and you're pretty sure the two of you will be best friends one day. Now, you're about to confidently head into an interview for a job you're dying to land.
Don't ruin it all by saying any of the following to your interviewer. 
"My last boss was an idiot"
No matter how terrible your last boss was, or how glad you are to be free of your previous company, keep it to yourself. Not only will you look immature and negative if you start griping, but you also never know whom your interviewer is connected to. Your interviewer and your former boss may be old fraternity brothers, for all you know.
"Do not gossip or speak badly about anyone you've worked with or for, even if they're currently serving time in state prison for what they did," says Gayl Murphy, author of "Interview Tactics: How to Survive the Media Without Getting Clobbered." "Even if the [interviewer tries to] push you into it. Remember, it's all a test. Be graceful and polite; you could be talking about [his or her] brother-in-law."
"Yes." "Yes." "Yes." "No."
Unless the interviewer asks you if you're so-and-so here for the nine-o'clock interview, you shouldn't be using one-word answers. An interview is your time to convince the employer that you have the qualifications for the job. Even if the questions don't seem open-ended, answer them as if they are. You don't need to drone on and on, but use every chance you get to prove why you're the right person for the job.
"You want to use as much color and detail as possible when describing your background, experience and your professional journey, but without being long-winded because, in reality, it's about your skill set and your valuable experience and expertise. Be specific: Use names, dates and places," Murphy says.
"Let me tell you what I think about religion and politics ..."
Like a first date, an interview is no time to bring up religion or politics. If these touchy subjects can spark heated debates among even the closest of friends, imagine what kind of argument you could get into with a stranger.
"When being interviewed for a job, deciding what to say and what to keep to yourself has always been challenging, especially since there are so many different opinions out there," Murphy says. "[But] unless you're going for a job as a pastor or rabbi, it's best to steer clear of religious tenets." Ditto for politics; unless it's a key part of the job, it's best to avoid sharing political opinions.
"Of course I know HTML coding/ my way around China/ the nuances of quantitative behavioral finance!"
An interview is not the place to embellish your work or personal experience. If an interviewer asks you about something you don't have experience with, fess up and tell him how willing and able you are to learn new things.  If you claim to be something you're not, chances are you'll be found out sooner or later – maybe not during the interview process, but when you find yourself lost in the middle of China a few months after landing the job, your gig will be up.
"Don't make up anything about what you've done that isn't true. It's too easy these days to get busted for anything like that. And they are looking at anything and everything," Murphy says.
"Hey man, do you want to grab a drink after this?"
No matter how well you hit it off with your interviewer or how great your conversation goes, your interviewer is not your friend -- even if you find out you're both getting married on the same day or you're both obsessed with college football. The relationship is still a professional one, so resist the urge to spill too many personal or off-topic details, or to start calling your interviewer "buddy,"  "girl," "hon" or "man."
"Hahahaaaaa! AAAAAhaaahahaaa!"
 OK, so someone cracked a joke. It's probable that in the duration of your professional career, you'll come across an interviewer with a good sense of humor. It's even OK to laugh at a joke made during the interview. Just don't die laughing. No one looks professional with cackle-induced teary eyes, teeth and  gums a-blazing.
Should you find yourself surpassing the point of no return in your fit of laughter, take a deep breath, and think about how awful you'll feel if you don't get the job. It may seem like a buzzkill, but there's a time and a place for everything, including hysterics.
"I mean, I'm not THAT great"
Now is not the time for modesty, false or otherwise. While you don't want to come across like a used-car salesman, you are there to sell yourself.  Or, as Murphy puts it, "Know in your bones you have an awesome product." And don't be afraid to sell it.

Regards
Raheel