No, you cannot bring him if you are not married. You cannot petition for someone who is not a legal relative or spouse. Additionally, since you are a green card holder, even if you do marry, you cannot confer any immediate immigration benefits upon him since there is a backlog in priority dates. However, if he is eligible, he can look into employment visa options or student visa options if he wants to study in the US.
Answered on Aug 30th, 2012 at 8:47 AM