be是一个连系动词,它有自己不同的形式
现在时:be 进行时:being 过去时:was/were 过去分词:been
它的后面必须跟形容词或名词作表语,与之构成系表结构,充当句子的谓语。
i am a student主语:i 谓语:am a student(系表结构)
being是它的现在进行时态,一般不单独用,而是用于现在进行时的被动语态。(being+动词过去分词)
the bike is being repaired.单车正在被修理中。
it is being finished by him这正在被他完成中。
been是它的过去分词,也不一般单独使用,而是用于现在完成时、过去完成时以及需要它的句子。
i have been here for a long time.我已经到这里有一段时间了。
至于你的问题,这与你想表达的意思有关。
你的工作是什么?
what do you do? what is your job?
那么这里选用do和is有什么根据呢?
第一句里面,第二个do是指你做什么,也就是你的工作,就是一个实义动词。按中文说,what you do已经足够了。可是英语里面就不行,必须跟一个助动词,也就是do.
这里就有了一个结论:当句子中有动词时,我们就用助动词do或是does.如果没有动词时,我们就选用is或是are,也就是b“Be”除了原形的“be”之外,还有另外七种形式:am, is, are, been, being, was, were.
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“ain't”, 但这并不是标准英语。
谈过了“be”作主动词的功能,现在看看“be”作助动词时,有些什么用法:
1.“Be + 现在分词”以组成进行式时态(Continuous Tenses),如:
15. Tony's maid is washing his new car.
16. The children are playing in the field.
17. Samuel was eating when I came in.
18. We have been living here since 1959.
2.“Be + 过去分词”以组成被动语态(The Passive Voice),如:
19. Her money in the drawer was stolen.
20. A number of good jobs are taken up byforeigners.
21. David studied in Taiwan but has been trained as a language lecturer in America.
22. Can all the wonderful birds be found in our Bird Park?
23. The disobedient boy was told to stand out- side the classroom.
24. Steps are being taken to reduce traffic con- gestion during peak hours.
25. Dishonest students will be immediately dealt with.
当陈述句的谓语是实义动词时,助动词do通常用于疑问句和否定句中。如:
I go to school every day.
我每天上学。
Do you go to school every day?
你每天都上学吗?
I don”t go to school every day.
我不是每天都上学。
另外,助动词do还可用于强调句中,用于强调谓语动词。如:
将助动词do及do 的相应形式放于动词前,而动词要用原形。又如:
I did tell him.
我的确告诉他了。
He does like playing football.
他的确喜欢踢球。
其余时候do作动词原形,表示做.