Be动词的否定
在 am , is , are , was , were 后面加not.
缩写式：am not , isn’t , aren’t , wasn’t , weren’t
1. The man isn’t back. 主系表结构
2. I am not back. be动词根据主语决定时态，单复数
3. They aren’t back.
4. He wasn’t back.
5. They weren’t back.
Be动词提问和回答
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.
Be动词的练习
1. 他是医生吗？(doctor)
Is he a doctor ?
2. 他们昨天在教室吗？（yesterday , classroom）
Were they in the classroom yesterday ? 通常时间放最后，地点在时间前面
3. 他们昨天不在教室。
They weren’t in the classroom yesterday.
Be动词的否定/提问/回答
Be动词的否定
在 am , is , are , was , were 后面加not.
缩写式：am not , isn’t , aren’t , wasn’t , weren’t
1. The man isn’t back. 主系表结构
2. I am not back. be动词根据主语决定时态，单复数
3. They aren’t back.
4. He wasn’t back.
5. They weren’t back.
Be动词提问和回答
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.
Be动词的练习
1. 他是医生吗？(doctor)
Is he a doctor ?
2. 他们昨天在教室吗？（yesterday , classroom）
Were they in the classroom yesterday ?
3. 他们昨天不在教室。
They weren’t in the classroom yesterday.