be动词有哪些？英语

Question

如题所述

Answer 1

am /is /was
are/were
being
(一)am,is和are用于不同的人称和数.
am用于第一人称单数.例如:I am a teacher.我是一名老师.
is用于第三人称单数,没有人和物的区别.例如:
—Who is he?
—He is Tom’s father.
—What’s this?
—It is a book.
are用于第二人称单、复数和第一、三人称的复数.例如:
You are a student. We are students, too.
(二)am,is和are可以帮助构成否定句和疑问句.
在am,is或are之后加上not,即将句子变成了否定句；把be动词提到句首,即将句子变成了疑问句.例如:
I’m from China. →I’m not from China. →Are you from China? (对I am的提问比较特别)
He’s thirteen years old. →He isn’t thirteen years old. →Is he thirteen years old?
They are policemen. →They aren’t policemen. →Are they policemen?
看了以上例句,一定要注意am,is和are在句中的缩写形式.
另外,am,is,are与this,these,those在一起时一般不缩写.
(三)be也可以位于句首,表示向别人提出要求.例如:
Be a good student! 做个好学生!

Answer 2

am,is,are