"Could you learn every language in the world? Could you run an all-night race? Could you recognize your family with your eyes shut? What is the best thing about you?"A uniquely charming book of questions and possibilities to get readers laughing, thinking, talking, drawing, writing and exploring the world.

Could you VS would you?

'Could You' is considered to be an informal way of asking something, contrary, 'Would You' is a formal way of requesting someone to do something.

Would you could you polite?

Yes, "could you" is technically asking if the person is able, rather than if they are willing. But unless the context indicates that you are referring to ability, people almost always understand it to mean the same as "would you". I think both are equally polite.