The verb "can"
Use
Can is a verb that is very often used in the English language. We use it when we
- express that someone is able to do something: He can speak Spanish.;
- express that something is possible: The kids can stay at our place after school.;
- ask for something: Can I have some water, please?;
- ask for or give permission: Can I go to the party tonight? Yes, you can go.;
- offer to do something: Can I help you?.
Statements with can
The verb can always requires the infinitive form of the following verb:
She can swim. They can go. We can meet you there, okay?
Rule: Noun/pronoun + can + infinitive + ….
Can has only one form. It does not change with he, she, it:
- I can
- You can
- He, She, It can
- We can
- You can
- They can
The "negative form" of can is can't or cannot:
You cannot go to that party! She can't speak English. I can't call you because my phone is out of order.
Questions with can
Remember that we ask a Yes/No Question using the verb "to be": form of to be + noun/pronoun + …? Are you tired?
The same rule applies for questions with the verb can: can + noun/pronoun + verb + …?
She can swim. 
Can she swim?
I can help you. Can I help you?
Anna can speak German. Can Anna speak German?
Can she swim?
I can help you. Can I help you?
Anna can speak German. Can Anna speak German?Short answers with can
You can answer questions with Yes, I/you/he/she/it/we/they/… can. or No, I/you/he/she/it/we/they/… can't.:
Can you swim? Yes, I can.
Can I help you? Yes, you can.
Can Peter speak Spanish? No, he can't.
Yes, I can.
Can I help you? Yes, you can.
Can Peter speak Spanish? No, he can't.Although can't is the short form of cannot, you usually don't use cannot in short answers without a verb following. With cannot, the answer would be longer:
Can Peter speak Spanish? No, he cannot speak Spanish.
No, he cannot speak Spanish.Give brief answers to the questions using the verb can. Keep the pronoun. Example: Can she read? Yes, she can. or No, she can't.
Yes, she can. or No, she can't.Write questions or answers with can. For example: Can they fly? Yes, they can fly. / No, they can't fly. Look at the pictures for help.
Yes, they can fly. / No, they can't fly. Look at the pictures for help.