系动词Be(am, is, are)的用法
一、请记住以下口诀：
我用am，你用are，is连着他，她，它； 单数名词用is，复数名词全用are。 变疑问，往前提，句末问号莫丢弃。 变否定，更容易，be后not莫忘记。 疑问否定任你变，句首大写莫迟疑。 二、Be动词在一般过去时中的变化：
1．am 和is在一般过去时中变为was。（was not = wasn’t） 2．are在一般过去时中变为were。（were not = weren’t） 3．带有was或were的句子，其否定、疑问的变化和am,is, are一样，即否定句在was或were后加not，一般疑问句把was或were调到句首。
相关练习题
一、用am, is, are 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? 8. Mike and Liu Tao ___ at school. 9. Whose dress _____ this? 10. Whose socks ______ they? 11. That ______ my red skirt. 12. Who _____ I ?
13.The jeans ______ on the desk. 14.Here__ ____ a scarf for you. 15. Here _____some sweaters for you.
16. The two cups of milk ______ for me. 17. Some tea ________ in the glass. 18. Gao shan's shirt _______ over there.
19. My sister's name ___ Nancy.
20. This ______ not Wang Fang's pencil.
21. _ ____ David and Helen from England? 22. There ______ a girl in the room. 23. There ______ some apples on the tree. 24. __ ____ there any kites in the classroom? 25. ______ there any apple juice in the bottle? 26. There ______ some bread on the plate.
27. There _____ a boy, two girls, three men and ten women in the park.
28. You, he and I _____ from China. 二、用be动词的适当形式填空
1. I ____was___ at school just now（刚才）. 2. He __ was_____ at the hotel last week. 3. We ___were_____ students two years ago.
4. They ___were_____ on the farm a moment ago(刚才). 5. Yang Ling ___was_____ eleven years old last year. 6. There ___was_____ an apple on the plate yesterday. 7. There ____were____ some milk in the fridge on Sunday. 8. The phone ___was____ on the sofa yesterday evening. 9. I ___was___ an English teacher now. 10. She ___was____ happy yesterday.
11. They ___were____ glad to see each other last month. 12. Helen and Nancy ___were____ good friends. 13. The little dog __was______ two years old this year. 14. Look, there ___were_____ lots of grapes here.
15. Today ___is____ the second of June. Yesterday __was____ the first of June. It ___was___ Children’s Day. All the students __were___ very excite
am, is, are的用法
1. is和are可分别与not缩写为isn’t和aren’t，但am却不能与not缩写为amn’t ，虽然有人把它缩为ain’t，但这毕竟是规范的口语说法，不宜仿用。
2. 陈述部分为第一称肯定式时的反意疑问句，通常用aren’t如：
I’m late, aren’t I?我迟到了，是吗？
3. 不要认为在主语之后总是用am。试看：
Both he and I are right. 他和我都对。或他和我都不对。 Neither he nor I am (或are) right. 他和我都不对. \"I\" is an English letter. I是英语字母。
4. 当am, is are 位于句末时，均不能与主语缩写。如： Tell me where he is (不能用he’s )。告诉我他在哪儿。 He is taller than I am (不能用I’m )。他比我高。 A：Are they watching TV? 他们在看电视吗？ B：Yes, they are. (不能用they’re)是的。
注：若其后有not时，am, is, are则可以与主语缩写，其中is和are 也可与not 缩写。如：
Are they watching TV? -No, they’re not (或they aren’t).
