English definition of “could”
strong /kʊd/ weak /kəd/ modal verb
CAN › used as the past form of 'can' to talk about what someone or something was able or allowed to do: I couldn't see what he was doing. You said we could watch television when we'd finished our homework.
POSSIBLE › used to talk about what is possible or might happen: The baby could arrive any day now. This kind of crime could easily be prevented. She could have (= might have) been seriously injured.
ASK › used to ask someone politely to do or provide something: Could you lend me £5? Could I have another drink?
ASK PERMISSION › used to ask politely for permission to do something: Could I speak to Mr Davis, please?
SUGGEST › used to make a suggestion: You could try painting it a different colour.
I could (have) › used when you feel so happy, sad, angry, etc that you would like to do something: I was so grateful I could have kissed her!