Be 动词的用法：
(1) Am--was Is --was Are--were 口诀：我用am, 你用are, is用在他她它，复数全用are。
(2) 肯定和否定句 I am (not) from London. He is(not) a teacher. She is(not) in the dining room. My hair is(not) long. Her eyes are(not) small.
(3) 一般疑问句 Am I a Chinese? Yes, you are. No, you aren’t. Are they American? Yes, they are. No, they aren’t. Is the cat fat? Yes, it is. No, it isn’t.
用恰当的be动词填空。
1. I ______ a boy. ______ you a boy? No, I _____ not.
2. The girl______ Jack's sister.
3. The dog _______ tall and fat.
4. The man with big eyes _______ a teacher.
5. ______ your brother in the classroom?
6. Where _____ your mother? She ______ at home.
7. How _______ your father?