Исправьте ошибки. you don't can go to the party. where do you must be? you can't use a computer? he can play chess when he was five. can i come in?

You can't go to the party.

Where you should be?

You can't use a computer?

He could play chess when he was five years old.

Can I come in?

Вроде бы всё правильно, но 2 предложение с конца мне кажется не совсем правильное)