一般现在时态：(I) am; (we\you\they) are; (he\she\it) is 现在分词：being（用于进行时态） 过去式：was（单数）、were（复数） 过去分词：been（用于完成时态）
在句子中,“be”可以是主动词(The Principal Verb)或助动词(The Auxiliary Verb). 当主动词时,“be”在性质上属于接系动词(The Linking Verb), 后面要有名词、形容词、地方副词或短语作补足语(The Complement).例如： 1. The man is a science teacher. 2. Mary's new dresses are colourful. 3. I have been there before. 4. Mother is in the kitchen now. 这四个都是陈述句,可以变成疑问句,方法简单,把主语和“be”或助动词对换位置即可： 5. Is the man a science teacher? 6. Are Mary's new dresses colourful? 7. Have I been there before? 8. Is mother in the kitchen now? 当“be”要在祈使句中出现时,它必须借重助动词“do”或“don't”之助,如： 9. Don't be silly! 10. Do be obedient! 11. Don't be a fool! “Be”有两种缩写法,如下： 12. He's not./He isn't. 13. You're not./You aren't... 但“am + not”的缩写法只有一个： 14. I'm not. 有人用“amn't”, 但这并不是标准英语.
1.“Be + 现在分词”以组成进行式时态(Continuous Tenses),如：
- Tony’s maid is washing his new car.
- The children are playing in the field.
- Samuel was eating when I came in.
- We have been living here since 1959.
2.“Be + 过去分词”以组成被动语态(The Passive Voice),如：
- Her money in the drawer was stolen.
- A number of good jobs are taken up byforeigners.
- David studied in Taiwan but has been trained as a language lecturer in America.
- Can all the wonderful birds be found in our Bird Park?
- The disobedient boy was told to stand out- side the classroom.
- Steps are being taken to reduce traffic con- gestion during peak hours.
- Dishonest students will be immediately dealt with.