Are the following two sentences correct?
1) Not only is John rich, but Jack is rich also
2) Not only does he love jogging but also swimming
Whatever comes after the "not only," you must use the same structure after "but also."
Not only does he love jogging, but he also loves swimming. You have a full subject/verb, so you need a subject verb.
He loves not only jogging, but also swimming. You have only the object after "not only" so you put only the object after "but also."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.