He is really good/well guitar player

He is really a good guitar player. (adjective).

He really plays the guitar well. (adverb).

Is he really good guitar player?

Who is really good guitar player?

What is he?

Is he or are you really a good guitar player?

Is he really a good or bad guitar player?

Is he really a good guitar or piano player?

Is he really a good guitar player or a singer?

He is really a good guitar player, is not he?