person A: you know at work_comma_ one of my coworker is always singing to himself_comma_ it bugs me
person B: Oh dear_comma_ but are you allowed to sing at work? That must be so annoying.
person A: it really is_comma_ he thinks he knows how to sing_comma_ i would not be so annoying if he knew how to sing 
person B: He needs to just sing in the shower. Tell him to quit singing.