Grammar reference: ‘can’ and ‘could’: possibility 1
Elephants CAN BE very dangerous- general fact
A hundred years ago, flu COULD BE very dangerous- fact about the past
Your keys COULD BE in your other jacket- guess about the present
They’re 30 minutes late. They COULD HAVE GOT lost- guess about the past
This bill CAN’T BE correct. It’s too much- impossibility: present
You CAN’T/COULDN’T HAVE SEEN me yesterday. I was at home all day- impossibility: past
They arrived over an hour late. They COULD HAVE PHONED us!- past event that was possible but didn’t happen
Grammar reference: ‘can’ and ‘could’: possibility 2
1. Elephants can be very dangerous.
2. A hundred years ago, flu could be very dangerous.
3. Your keys could be in your other jacket.
4. They’re 30 minutes late. They could have got lost.
5. This bill can’t be correct. It’s too much.
6. You can’t have seen me yesterday. I was at home all day.
7. They arrived over an hour late. They could have phoned us!
Grammar reference: ‘can’ and ‘could’: other uses 1
My father CAN PLAY the violin.- ability: present
My mother COULDN’T DRIVE until she was 40- ability: past
CAN I MAKE a suggestion?- asking for permission
COULD I USE this phone for a moment?- asking for permission: more polite
You CAN HAVE a break now- giving permission
You CAN’T PARK here- no permission
CAN YOU GIVE this letter to Fay?- requesting
COULD YOU PASS me the salt, please?- requesting: more polite
I CAN DO the shopping if you like.- offering
COULD I MAKE you a cup of tea?- offering: more polite
Grammar reference: ‘can’ and ‘could’: other uses 2
1. My father can play the violin.
2. My mother couldn’t drive until she was 40.
3. Can I make a suggestion?
4. Could I use this phone for a moment?
5. You can have a break now.
6. You can’t park here.
7. Can you give this letter to Fay?
8. Could you pass me the salt, please?
9. I can do the shopping if you like.
10. Could I make you a cup of tea?