Chris presents some ideas about different ways to use can, could and to be able to. Via YouTube
CAN = modal verb
I can do it or I can’t (cannot) do it
can’t use it in the past
can for permission: Can I go out? You can’t smoke here (instruction)
can for ability: I can speak three languages or I can’t speak three languages
can in the future: I can see you tomorrow
COULD = can in the past (modal verb)
I could come or I couldn’t (could not) come (past)
could for questions (more polite):
Could you do that outside, please?
could = can in the past: I could do that when I was younger
couldn’t for something you don’t want to do:
I couldn’t make fun of him (it is possible but I don’t want to)
TO BE ABLE TO is possible with the past and future – not a modal verb
able – ability (noun)
I’m able to see him now or I’m not able to see him now
use with future + will:
I will be able to come tomorrow
I won’t be able to come tomorrow
use to be able to in the past:
I was able to do that when I was younger
I used to be able to do that
‘can’ is more common than ‘be able to’ because it’s shorter and more useful
