You will be asked some tough questions at your next job interview and how you answer will determine if you get the job. Knowing why an interviewer asks a particular question is the first step to determining how to answer it.
What are your strengths and weaknesses?
Why they ask: They want to know what you bring to the table and how you can answer this tricky question.
Find a way to showcase your strengths by giving examples of what you've accomplished in the past. If they ask for strengths, as in the plural, make sure you list at least 2 or 3. Focus on work examples that made a positive impact on your past company. Your weaknesses should also have a positive spin. State how you overcame a weakness by showing you were aware of it and illustrate that now, because you've made some conscious changes to improve your skill, it's actually a strength for you.
Do you prefer to work by yourself or as part of a team?
Why they ask: They want to know if you can work unsupervised and if you get along well with others.
Find a way to show that you can do both sucessfully. Give examples to illustrate how you shine working by yourself and within a team. Show how you're independent, but you're also great with people in a project or group situation. By showing the interviewer that you're adaptable, they know you'll be a flexible worker and will be able to be effective even if the work situation changes.
Why did you leave your last job?
Why they ask: They really want to know.
Find a creative way if telling them the truth. You don't want to lie or bend the truth. But you can be diplomatic and professional and still come out looking like a good candidate. Some good answers (if they are the truth!) are "I left to find a more challenging position where I could fully use my skills," "The company restructured and my position was redefined," or something of the like. Both those answers put a positive spin on leaving a job. Try to do the same for your reason.
What do you think this job involves?
Why they ask: They want to know if you've done your research.
Hopefully you have and you're able to give them a good definition of how you see this job. Don't quote directly from the job description because anyone can do that. Try to interpret what the job description is saying and try to figure out the skill sets tehy are looking for. Then, illustrate how yours match perfectly.
How did your last job prepare you for this job?
Why they ask: They want to know what your skill sets are and how you apply your knowledge. They also want to know how much training you'll need.
Tell them exactly what they are looking for. Use the skills required section of the job description to illustrate how your experience fits this job. If this job is very similar to your last one, show them, using examples that you have the training it takes to do the job right now.
You will likely be asked a lot more questions than this. Answering them requires you to find out why they are asking you. By figuring out why questions are asked, you can better prepare yourself and answer them in a way that projects you as the perfect candidate.