- What’s the difference between CAN and COULD?
Let’s look at CAN and COULD in 5 different steps:
- ability
- possibility
- permission
- request
- offer
First, it’s important to remember:
1.ABILITY – Do you have the skill or talent?
CAN = present ability
- I can speak English very well.
I have this ability. - I can party all night, every night.
I have this ability. - I can make the world’s best tiramisu.
I have this ability. - Basketballers can jump very high.
They have this ability. - Cheetahs can run very fast.
They have this ability.
COULD = past ability
- I could speak English very well.
I had this past ability. - I could party all night, every night.
I had this past ability. - When I was at uni, I could study for hours. Now I can’t.
I had this past ability. - My gran could make the world’s best tiramisu.
She had this past ability. - In the past, everybody could speak Sardinian. Now, many young people only speak Italian.
This was a past ability.
2.POSSIBILITY – Is something possible to do?
CAN = present possibility
England can be very expensive.
This is possible.
Be careful. The noodles in this restaurant can be very spicy even though I always say ‘No chili please!’.
This is possible.
If you can’t find what you need here, you can probably find it on Amazon.
This is possible.
COULD = possibility in general.
You can use ‘could‘ for the past, present or future. The context of the situation/ sentence will tell you if ‘could’ is referring to the past, present or future.
My granddad could either be a very nice person, or he could be a horrible person. It always depended on the day.
These are two past possibilities.
When I was child, you could actually still see traditional chimney sweeps!
This was a past possibility.
30 years ago, you couldn’t travel so easily. We didn’t have cheap airlines like EasyJet or Ryanair.
This was not possible in the past.
Oh no, where are my keys? Hm…they could be in my jacket pocket.
This is a present possibility.
I wonder what my best friend from high school is doing now? She could be married. She could still be living in New York.
These are two present possibilities.
If we don’t want to cook tonight, we could go out. What do you think?
This is a future possibility.
According to the forecast, it could get as low as -5C tomorrow!
This is a future possibility.
COULD HAVE + PAST PARTICIPLE
We use ‘could have + past participle‘ when we are speaking about a past hypothetical situation. This is something that did NOT happen.
Situation: Your mum is angry at you for drinking alcohol and driving.
Example: You could have crashed! You could have died! You could have damaged my car!
This is all hypothetical. You did not crash – You did not die – You did not damage the car.
You know, I could have been a professional footballer. But, my parents never supported me.
This is hypothetical. You did not become a professional footballer.
On the phone:
A: Hi Jim, where are you? I’ve been waiting here for over half an hour!
B: Oh sorry Anne, my boss is making me work late tonight.
A: What? You could have called me to tell me! How long were you planning on letting me wait?
This is hypothetical. Jim did not call Anne.
3. PERMISSION – Are you allowed to do something?
CAN = informal permission
COULD = formal permission
Can I borrow your phone? (informal)
Could I borrow your phone? (formal)
Can I take your picture please? (informal)
Could I take your picture please? (formal)
We only use CAN when we give permission. Not COULD.
☑ Yes you can use my phone.
Yes you could use my phone.
☑ Of course you can take my picture.
Of course you could take my picture.
4.REQUESTS – Do you want someone to do something for you?
CAN = informal request
COULD = polite request
(Both are polite if you use ‘please’, but CAN is more informal.)
Can you close the window please? (informal)
Could you close the window please? (more polite)
5.POLITE OFFER – Can you help someone?
Use either CAN or COULD!
I can/could drive you to the airport if you need me to.
I can/could help you with your essay if you want.
Can/Could I get anyone another drink?
