Modal verbs can versus could
December 12, 2006 6:20 PM Subscribe
English grammar: 'could be Xing' versus 'can be Xing' -- how can we explain why one is correct and one isn't?
posted by stavrosthewonderchicken to Writing & Language (23 answers total) 6 users marked this as a favorite
(Somebody fire up the languagehat signal!)
I'm trying to figure out a reasonably succinct structural way explain why one of these is just fine, but one isn't.
We're using modals here to express probability or guessing. Scenario: you call your wife at home, but there's no answer. You guess that she might be in the bathroom, and express it by saying "She could be taking a shower." I say this is correct.
Saying "She can be taking a shower" in this situation, I call incorrect, but I can't seem to hit on any plausible explanation for why, other than that it's just common usage. That's a good enough answer, perhaps, but I'd like to actually understand what's happening here, structurally. It could be that my brain is just wobbly today, and I'll figure it out as soon as I post this, but it's driving me a bit nuts.