Change the sentence with can/could
You're on a train. The woman next to you has finished reading her newspaper. Now you want to look at it. What do you say?
Could I take a look at that newspaper when you're done with it?
The blaze can (to see) far away now.
be seen
My grandmother loved music. She ___ play the piano very well.
could
Can you help me carry these boxes upstairs?
Request
The person in the next room has some music on very loud. How do you ask him politely to turn it down?
Could you turn the music down?
Could they still (to play) billiards?
be playing
You can't park here; it's a no-parking zone.
Prohibition
Make a suggestion.
What should I give Ann for her birthday? (a book)
You could buy her a book.
I needn't have lived so harshly for an extra twenty pounds a year. I could (to soften) things for myself.
have softened
The boy felt into the river, but fortunately we ___ rescue him.
were able to
He can’t be serious about quitting his job.
Incredulity, doubt
Put the sentence into reported speech.
Could you give me your pen?
They asked if I could give them my pen.
Can he (to walk) all this time? He went out three hours ago.
have been walking
I looked very carefully, and I ___ see a figure in the distance.
could/was able to
Can she be playing tennis that long?
Surprise, astonishment
Put the sentence in the past.
Can it be that he speaks 10 languages?
Can/could it have been that he spoke 10 languages?
He cannot (to think) of this himself who suggested it to him?
have thought
He had hurt his leg, so he ___ walk very well.
couldn't/wasn't able to
He could be at the gym; he goes there around this time.
Possibility, supposition