I've read that 'can and could' can be used to imply "to be able to do something in present and past time reference, but sometimes I'm confused to use them. The most confusing situation is as follows:
Context: When I'm not sure that I/he/she/it/they can do or able to do something in present or I/he/she/they don't want someone to do something fully or when hedging/softening the sentences.
- you/I could write an essay.
- I/you could go to school.
- I/you could re-rewrite this sentence.
- I could call you a daughter.
these sentences imply present ability or past ability? I think they imply both present and past ability, but I don't understand their real meanings.
*can we use 'could' to talk distancing ourselves what we say or when we want to be indirect of what we say?