sentence 1: How do I know if I'm good?
 sentence 2: How do I know what I'm good at? sentence 1: Can a person increase his/her height even after 20?
 sentence 2: Is it possible to increase the body height after 20? sentence 1: Is it possible to find an owner of a car by license plate?
 sentence 2: How do I find out the name and address of a car owner by using just his license plate number?
not same meaning
same meaning
same meaning