"If someone is knocking at the door now, it would be / could be Tom."
Although I have never heard of this kind of sentence before, I think the kind of the sentence is okay and natural in some context. Do you native English speakers agree with this? Thank you so much as usual and have a good day.
Last edited by sky3120; 14-Dec-2012 at 03:18.
They could work in certain contexts, though will is more likely than would.