am is are的否定形式縮寫
Be動詞的否定
在 am , is , are , was , were 後面加not.
縮寫式:am not , isn’t , aren’t , wasn’t , weren’t
1、 The man isn’t back. 主系表結構
2、 I am not back.
be動詞根據主語決定時態,單複數
3、 They aren’t back.
4、 He wasn’t back.
5、 They weren’t back
Be動詞提問和回答
Is he a teacher ?
Yes , he is. / No , he isn’t.
Are you a teacher?
Yes , I am / No , I am not.
Were they teachers?
Yes , they were . / No , they weren’t.