Things that interviewers say that mean you won’t get the offer might include "We are interviewing a number of other candidates," or "Competition for this position is very tough," or "We will reach out with next steps when we finish interviewing all other candidates." If the interviewer response is vague or non-committal, there is a chance you won’t get the offer.
Generally speaking (though not always), if your interview is very short—think 10 or 15 minutes—it is unlikely that an offer will be forthcoming. If you were told prior to the interview that the interview would last two hours and your interview ends after 30 minutes, then it is unlikely you will receive a job offer. If the interviewer says they will keep your resume on file for future opportunities, there’s a very good chance you won’t get the job offer. Regardless of the situation, you should always be polite and follow up with a thank you. You never know when there might be a suitable opportunity for which you will be a fit.
If you sense (or know) that your responses to the interview questions were not good, spend some time evaluating your interview skills. Brush up on how to respond to common interview questions. Practice your responses with a friend or family member. Research interview questions that are typically asked of those interviewing within your particular field or industry.
You need to remain cognizant of the things that interviewers say that mean you will not get an offer. It is vital to avoid common interview mistakes, but sometimes, you did nothing wrong. You were simply a bad fit for the position. One common phrase is, "We are currently interviewing other applicants, so we will get back to you soon." Most of the time, this means you were not what the hiring manager wanted, and you should not expect a phone call back. Another typical phrase is, "We will keep your resume on file." Hiring managers never mean they will actually keep your resume. They are simply being polite. You also need to be mindful if the interviewer cuts the meeting short and says he or she has another meeting to attend. Generally, there is no other meeting to go to. The interviewer has simply realized you are not a good fit and does not want to waste any more time. It is entirely possible a hiring manager will say one of these phrases and still offer you the job, but you should not get your hopes up.