"Are you a good swimmer" and "do you swim well" both mean the same thing and sound fine to me, though the first one is maybe a bit more natural. The difference between these and your questions about driving and singing is that you are asking how good the person is at swimming as opposed to if the person has the ability to swim. The question "Are you a swimmer?" also makes me think you are asking about a job (or something similar). Specifically for your questions: 1. "Are you a driver?" makes me think you are asking about a job. "Can you drive?" is probably the best way to ask if the person has the ability to drive. If you are more interested in how well the person drives, you can also ask "Are you a good driver?" If the person can't drive at all, then the response should be "no" for both questions. 2. "Are you a singer?" makes me think you are asking about a job. The following do not make me think so: "Are you a good singer?", "Are you much of a singer?", "Do you sing?", "Do you sing well?"

OK Olga, just got back home, so I'll answer your question in detail now. "Can you drive?" does not mean the same as "Are you a driver?" "Can you drive?" can be interpreted in 2 ways: 1) "Can you drive a car," or "Can you drive this car?" - in the sense of whether they are actually able to drive a car 2) If you and the other person you are talking to already understand the context for your question. For example: if you and your partner are driving in a car, and you stop at a red traffic light. Then when the lights go green, you tell him "can you drive" (so that he drives the car) "Are you a driver?" - this can also mean a few things depending on the context. 1) The most common is when you ask someone this, it means, if they are a bus or a taxi driver (but again, depends on the context) 2) "Are you a driver?" can simply mean whether they are a driver of a vehicle, any vehicle, since it's not specific. But it will usually mean a car. To answer your question, which is, if you just want to ask someone whether they know how to drive, just say: "Do you know how to drive a car?" / or similarly "Are you able to drive this car?" "Are you a singer?" This almost always means "are you a professional singer?" I hope this helps.

Ill answer the second part later but the amswer to your first question is this: it means the same thing and people say both interchangably. More common to say 'are you a good swimmer' though

edit: on second thought, use the first one. "Good" is more precise in this context.