Ability
(Can/Would) you like some coffee?
Would you like some coffee?
(Can/Could) you give me a lift to the station? (formal)
Could you give me a lift to the station?
(May/Could) I go to the bathroom, please?
Could I go to the bathroom, please?
(Would/Can) I help you with that?
Can I help you with that?
(Can/Would) I park here?
Can I park here?