Student or Learner
I read this question somewhere before and have been puzzled about the original answer of 'couldn't':
---Have some more cake.
---Oh, I couldn't/ can't. Thank you.
I thought both answers are all right and I'm more likely to say 'I can't'.
Do both 'couldn't' and 'can't' sound all right in the reply? Could you explain why?
I was hoping a native English teacher could give me the answer. Thank you very much in advance.
Either is okay.
'couldn't' is usually taken to mean "I should not. It will make me fat!"
'can't' is more like "I am too full."