You always answer: Yes. Then explain briefly the reason why. A perfect reason includes a long-term goal in 3 – 5 years that you have achieved.
For example: I have strived to get excellent degree after graduate and to use majoring English fluently. Now I’ve achieved that goal.
Yes! With the experience that I have gained and the knowledge and skills that I have learned I could say that I have been successful in terms of providing helpful assistance and ideas to the people whom I owe my success and improvement both in my career and personal life.
Yes, I’m a successful person as you can say from my education background and working history. I manage myself well in my career path. As a job-oriented person, I always try my best to do my job whatever it is while committing to the highest performance as possible.