牛津译林版（2019）选择性必修 第一册Unit 1 Food matters Grammar and usage课件(共37张PPT)

(共37张PPT)
Unit 1
Food matters
变
型
To-infinitives as subjects
and predicatives
动词不定式作主语和表语
动词不定式的时态和语态
昊
m
2
动词不定式作主语
3
动词不定式作表语
1
动词不定式的语态
及时态
动词不定式的时态和语态
语态
主动
被动
时态
般式
to do
to be done
进行式
to be doing
完成式
to have done
to have been done
2
To-infinitive as subjects
To-infinitive as subjects动词不定式作主语
1.动词不定式作主语，表示具体的、一次性或尚未做的动作。如：
To cook Chinese food is not easy.
To speak English well isn't an easy job.
To talk with her is a great pleasure.
注
动名词形式作主语，表示动作经常反复发生，而不是只针对某一次。
Smoking in the public is not good.
2.动词不定式短语作主语时，为了保持句子平衡，往往用it作形式主语，而把
不定式短语置于谓语动词之后。如：
To master English is important.-It is important to master English.
Practice
1 To speak English well isn't an easy job.
-It isn't an easy job to speak English.
2To improve our teaching method is very important.
-It is very important to improve our teaching method.
3 To talk with her is a great pleasure.
It is a great pleasure to talk with her.
其常见句型有以下4种
It十is十名词+to do sth
It's our duty to take good care of the old.
②
It takes/took will take sb+some time/money+to do sth
It will take us three hours to walk there.
③
It+be+形容词+for/ofsb+to do sth
It's very kind of you to tell us what happened yesterday.
It is important for children to tell right from wrong at an early age.
It seems(appears)+形容词+to do sth
It seemed impossible to finish the work on time.