настоящее время:
I can (can’t, cannot) We can (can’t, cannot)
You can (can’t, cannot) You can (can’t, cannot)
He/She/It can (can’t, cannot) They can (they can’t, cannot)
прошедшее время:
I could (could not, couldn't) We could (could not, couldn't)
You could (could not, couldn't) You could (could not, couldn't)
He/She/It could (could not, couldn't) They could (could not, couldn't)