could strong /kʊd/ weak /kəd/ modal verb
A2 used as the past form of ‘can’ to talk about what someone or something was able or allowed to do: I couldn’t see him. You said I could go!
A2 used as a more polite form of ‘can’ when asking for permission: Excuse me, could I say something here? Could I speak to Mr Davis, please?
B1 used to talk about what is possible or might happen: She could arrive any time now.
B1 used as a more polite form of ‘can’ when asking someone to give you something or do something: Could you lend me £5? Could you turn the music down a little, please?
B1 used for making a suggestion: We could go for a drink after work tomorrow, if you like.