人教版（2019）选择性必修第三册Unit 1 Art Discover Useful Structures 课件（共17页）

(共17张PPT)
Discovering useful structures
Infinitives as the predicative and subject
（不定式做表语和主语）
动词
谓语
非谓语
done
doing
to do
具有动词的特征
具有名词的特征
具有形容词的特征
具有副词的特征
主语 谓语 表语 宾语 定语 状语 宾补
to do
一、不定式的句法功能

It is hard to give a precise definition.
Perhaps the best way to understand Western art is to look at the
development of Western painting over the centuries.
During the Middle Ages, the purpose of Western art was to teach people about Christianity.
...the main characters were often made much larger than everyone else to show their importance.
Discover
subject 主语
attribute 定语
predicative 表语
predicative 表语
adverbial 状语

He sought to show not just the outer image of his subjects, but their inner warmth and humanity as well.
What they attempted to do was no longer show reality, but instead to ask the question, “What is art ”
Discover
object 宾语
object 宾语
predicative 表语
1.基本形式： to+动词原形
2.其否定形式是: not/never to do.
3.注意：不定式没有人称和数的变化。
主动语态 被动语态
一般式
进行式
完成式
to do
to be done
to be doing
to have done
to have been done
二、不定式的基本结构
不定式作表语常用来解释或说明主语要去做什么事。主语通常是表示意向、打算、计划、建议等的词，如wish, idea, task, purpose, duty, goal, dream, job, suggestion等
三、不定式作表语
1. My dream is ___________(become) a painter.
2. My suggestion about improving English is ___________(memorize) words every day.
3. My duty is ____________(help) my students improve their English.
4. My next plan is ____________(take) part in a competition.
5. What the boys’ parents told them just now was _______________ (play) in the street. It was too dangerous.
练习
to become
to memorize
to help
to take
not to play
6. Whether to participate in that competition remains _______________(discuss) and decided.
7. His homework seems _________________(finish) before she came here.
练习
to be discussed
to have been finished
不定式作表语常用来表示”同意、安排、命令、决定、劝告、意愿、禁止等。
They are to marry next week.
You must be patient and persistent if you are to succeed.
You are to have a face-to-face talk with them.
Students are not to use mobile phone in school.
不定式作表语
（表安排）
（表愿望）
（表劝告）
（表禁止）
1.The question is how to carry out the plan.
2.The question is when to start the work.
3.The problem he faced is what to do.
四、疑问词+不定式作表语
What they want to do is have a good sleep.
五、不定式作表语to的省略情况
不定式作表语时，前面主语中出现实义动词do的各种形式，后面的不定式可省略to。口诀：前do后不to
1. My ambition is ___________ (work) in the computer industry when I grow up.
2. What I want to do is _______ (work) in the computer industry when I grow up.
3. The most important thing to do is _______ (conquer) yourself.
4. 李华似乎在来这里之前就已经感冒了。
__________________________________________________________
5. 这个活动的目的是满足普通人的需求。
__________________________________________________________
6. 现在的问题是什么时候去参加比赛。
__________________________________________________________
练习
to work
work
conquer
LiHua seemed to have caught a cold before he came here.
The goal of this activity is to meet ordinary people’s needs.
The recent problem is when to take part in the competition.
My task today is to take care of my little brother.
My mother’s task is taking care of my little brother.
六、不定式作表语和动名词作表语的区别
不定式作表语 强调的是________________________的动作
动名词作表语 强调的是_______________________的动作
一次性、具体的、将要发生
一般性、抽象的、经常发生
1. ___________________(如何使用计算机) is important.
2. _____________________(把这个箱子放在哪里) seems to hard to decide.
3. __________________________(什么时候去展厅) is not decided.
七、疑问词+不定式作主语
How to use computer
Where to put the box
When to go to the exibition hall
七、it代替不定式作主语，即形式主语(导学案P116)
It作形式主语常用的结构：
1. It is/was+ adj.+ for sb to do sth.
2. It is/was +adj. + of sb to do sth.
3. It is/was +(a/an) +n. +to do sth.
4. It takes/costs sb sometime/money to do sth.
练习
1. ___________(save) time is to lengthen life.
2. It cost him no money ___________(watch) the movie.
3. It is a great honor for me ______________(invite) and make a speech.
4. How ___________(stop) polluting this important river is a big problem.
5. It is considerate of you ____________(keep) the poor child cpmpany before his parents are found.
To save
to watch
to be invited
to stop
to keep
练习
1. 作为一个老师，我的职责是为我的学生树立一个榜样。
_____________________________________________________
2. 成为东道主对我们来说是一项巨大的荣誉。
_____________________________________________________
3. 每个人都学习和掌握一些实用技能是很重要的。
_____________________________________________________4. 昨晚锻炼花了我一个多小时。
_____________________________________________________
As a teacher, it’s my duty to set an example for my students.
It’s our great honor to be the host of the Olympic Games.
It’s very important for everyone to learn and master some practical skills.
It took me more than an hour to take some exercise yesterday evening.