The objective of the interviewers is to know more about of yourself, your behaviour, your goals and achievements and lastly your career plans. So when sometimes we respond to the questions ask by the interviewer it must have the facts to the questions, not try bush around as this interviewers has heard every clichéd of the answer to this question.
Never interfered with the question ask by the interviewer during half way even if you know the answer or even you understand what he is going to ask. Waited until he has completed his question, then answer the question as a show of respect and also when answering the question try to use a courteous tone and the tone and the words must not sound aggressive. Sometimes you do not know the question ask, tell them about your ignorance rather then created a answer that might cost you the jobs.
Questions that are most asked by the interviewers are why did you left the old jobs.It might be a simple question ask but sometimes it might cost you the job if you are interview for a high position like having trouble getting along with people since you’re going to be constantly working with others. Others question ask are why you are interest in this company, It is best to do some researched and get some imformation of the company plans and its future. Also keep your answer factual and brief and focus your interviewer and don't move yourself too much and look around.