asking someone to do something
Can you tell me the way to the museum?
Can we have two coffees, please?
talking/asking about if it's OK to do something
You can't smoke in this restaurant.
Can I leave early today, please?
giving/asking for advice
What do you think I should do?
You shouldn't work so hard - you're always tired.
talking about ability
I can speak English but I can't write very well.
How many languages can you speak?
offering to help
Can I carry those bags for you?
Can I get you something to drink?
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