Hi, do you mean, " How do I determine whether a person has similar interests to mine?" As Cherry said, you need to ask the person whether they enjoy doing the same things as you do.

If he/she say so

Hello Kaulitz89, The sentence you wrote first is more appropriate to use. It is not correct to say " How to determine whether a person is really like to own". This part " like to own" sounds like a literal translation from Chinese to English. Otherwise I can't answer this question because I don't understand it well. I am sure you don't mean someone absolutely like you ,rather who shares hobbies ,interests or point of views with you ?!?