" I guess you could say there might be some difference in tone, "couldn't" being smoother: Alice: There is no way to get a napkin. Greg: Can't …? or Alice: The napkin holder is empty, and I have chocolate on my face.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
They can be pretty much the same, meaning "Isn't it possible to get some napkins from the bar?" I guess you could say there might be some difference in tone, "couldn't" being smoother:
Alice: There is no way to get a napkin.
Greg: Can't …?
or
Alice: The napkin holder is empty, and I have chocolate on my face.
Greg: Couldn't …?
They can also be different
ty123 What’s the difference: Can’t/couldn’t you get some napkins from the bar?
'can' is present; 'could' is past.
Isn't it possible to get napkins ...? Are you not able to ...?
Wasn't it possible to get napkins ...? Were you not able to ...?
Also, in other contexts, 'couldn't' is a more polite form of 'can't'.
CJ