As you applied for and were invited to interview for this role as a Corporate Trainer, your interviewer has a very good sense of your strengths from your resume. Your interviewer is also aware that every candidate that they interview has weaknesses that show up in their professional life. If asked a question like this during your interview, remember that it is not meant to place focus on the ways you are weak or unskilled. The purpose of the question is for your interviewer to see if you are a future employee that has a strong character and who is working to improve professionally. Your interviewer also wants to ensure that your biggest weakness is not a vital part of your role as a Corporate Trainer with their organization. Pick one weakness and be sure you have an action plan in place for improvement. Be prepared to communicate your weakness without embarrassment. You should also clearly demonstrate how the lessons you learned and your effort to improve will add value to this organization.