CAN
1. Talks about ability
She can dance.
I can swim.
I cannot paint well.
I can speak English well.
2. Giving command or orders,
to ask somebody to do something
Can you please send this mail to this address?
Can you lock the door.
Can you turn it off, please?
3. To ask permission
Can I smoke in this room?
Can I use the bathroom?
Can I have this seat?
Can we use this room for a while?
COULD
1. Past Ability
I could play the piano well when I was 12.
She couldn’t swim at first.
He couldn’t lift a heavy weight.
He couldn’t understand English before.
2. Giving requests or orders
- Could is more polite and formal than can.
- Using can or could in giving orders is OK.
- It’s in question form.
Could you please drop this mail before you go home?
Could you turn off the light?
Could you hang this outside, please?
3. Asking a Favor
- especially for difficult tasks
- we use could since it is polite.
Could you tell me where Madison Avenue is?
Could you take me to this address?
Could you help me with the house chores?
Could you babysit for me while I work?