译林版(2019)选择性必修第一册Unit1 Food matters Grammar and usage动词不定式作主语和表语课件（共25张PPT）

(共25张PPT)
Unit 1 Food matters
Grammar and usage
GRAMMAR
To-infinitives as subjects and predicatives
App’s functions
(5) ________
In the last few weeks, the author engaged in home cooking.
Benefits
In the past, the author liked to eat (1) _______________.
Why
The author is eager to try new restaurants.
To eat out was also a social activity to (2) _______________________ with friends.
Then the author came across a cooking app last month.
There are lots of (3) _______ to choose from.
It offers (4) _________________ for users to follow step by step.
to cook exactly the author wants
(6) _________
at the restaurant
enhance the relationship
recipes
detailed instructions
cheaper
healthier
Lead-in
Phrases
L1-2 be eager to do sth
L2-3 allow sb to do sth
L4 come across
L4 a variety of
L9 throw oneself into
L11 no wonder
倒数L3 a couple of
渴望做某事
允许某人做某事
偶然遇到；偶然发现
各种各样的
投身于，热衷于
不足为奇，难怪
几个...
As a real foodie, I enjoy all kinds of foods. My dream is to try different restaurants and taste various foods.
Yesterday I invited some friends to try a great new restaurant for dinner.
Nothing can stop our determination to have a try. We decided to wait outside.
After an hour of waiting, we were invited to go into the restaurant and take the order.
The dishes are extremely delicious. It is worthwhile to have such a long wait.
Lead-in
Find out to-infinitives and guess their functions.
表
宾
主
补
补
A REVIEW
动词不定式一般由“to+动词原形”构成，其否定形式是“not to do”。动词不定式可以带宾语或状语构成动词不定式短语，没有人称和数的变化，但有时态和语态的变化。动词不定式不能单独作谓语，可以作主语、宾语、表语、定语、补语等。如：
To finish the task in a week is very hard.
The big boy managed to pass the exam.
My work is to clean the garden every day.
She was the first woman to swim across the English Channel.
Tell him to come here the day after tomorrow.
主
宾
表
定
补
Exploring the rules
Below is a blog entry about eating out and eating at home. Find the sentences that use to-infinitives as subjects or predicatives.
Complete the table of Part A on Page 6.
To-infinitives as subjects To-infinitives as predicatives
To eat out was also a social activity, allowing me to enhance the relationship with my friends.
When I picked a popular recipe and gave it a try, I discovered that it was not that difficult to make a simple and tasty dish.
Not that long ago, my first thought at mealtimes was to eat at a restaurant.
My plan is to invite my friends over at the weekend to show them my new-found skills.
When the to-infinitive is used as a subject, we usually use the preparatory subject (1) at the beginning of the sentence.
The to-infinitive can also be used as a predicative. It usually comes after the verb (2) .
Exploring the rules
it
be
Work in pairs. Identify what to-infinitives function as in the following sentences from the blog entry of Part A.
(1) To eat out was also a social activity, allowing me to enhance
the relationship with my friends.（L2）
(2) There are a variety of recipes on the app to choose from.(L4)
(3) My plan is to invite my friends over at the weekend to show
them my new-found skills.(倒数L2）
object complement
attributive
adverbial of purpose
Exploring the rules
01
used as subject
1. 动词不定式作主语，表示具体的、一次性的或者表示将来含义的动作，且谓语动词常用单数。如：
To master a new skill is not an easy thing.
To see is to believe.
To help others is our duty.
To talk with her is a great pleasure.
01
used as subject
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，而将动词不定式短语置于句末。如：
It is important to enlarge English vocabulary.
It would be a waste of time to look up every new word when you read an English novel.
其常见句型有以下4种：
① It＋is＋n.＋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＋adj.＋for/of sb＋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.
④ It seems (appears)＋adj.＋to do sth
It seemed impossible to finish the work on time.
01
used as subject
用 it 做形式主语改写下面句子
(1) To speak English well isn't an easy job.
(2) To improve our teaching method is very important.
(3) To talk with her is a great pleasure.
(4) To look up every new word would be a waste of time.
It isn’t an easy job to speak English.
It is very important to improve our teaching method.
It is a great pleasure to talk with her.
It would be a waste of time to look up every new word .
01
used as subject
3. “特殊疑问词 + 不定式” 构成的不定式短语作主语时，且谓语动词常用单数。常见的特殊疑问词有：what , who , which , when , where , why , how 等。如：
Where to hold the meeting hasn’t been decided.
How to relieve the pain is a question.
单个不定式(不定式短语)做主语，谓语动词用单数
To play basketball ______(be) great.
如果and连接两个或更多并列的不定式(不定式短语)作主语，谓语动词就用复数
To improve people’s life and to speed up socialist construction ______ (be) our two important tasks.
When and where to do ________________________ (not decide) yet.
What to do and where to do ___________________________ (not decide) yet.
is
are
hasn’t been decided
haven’t been decided
02
used as predicative
1. 动词不定式作表语，通常说明主语的具体内容。
其主语通常是 aim, ambition, dream, duty, goal, idea, intension, plan, purpose, task, way ,wish 等表示意向、打算、计划的词。如：
His ambition is to become an actor.
Her duty is to look after the children.
不定式作表语通常可以和主语位置互换。
My dream is to be a doctor.＝To be a doctor is my dream.
02
used as predicative
2. 某些系动词，如be（是）、seem（看起来）、appear（看起来）、prove（证明）、turn out（结果）等，后面可以接不定式作表语。
其中，除了be动词之外，seem、appear、prove、turn out后面的表语若是以“to be+...”的形式出现，通常可以省略to be。
He seems (to be) busy. ＝He appears (to be) busy.
The plan proves (to be) right. ＝The plan turns out (to be) right.
Attention : 有些系动词，如sound（听起来）、smell（闻起来）、taste（尝起来）、feel（感觉）、become（成为）等，通常不可以接不定式作表语。
练习：判断下列句子正误
It smells to be delicious.
The book seems available.
The cake tastes to be yummy.
F
T
F
02
used as predicative
3. “特殊疑问词 + 不定式”通常与be动词构成系表结构，作be动词的表语。如：
The question is how to carry out the plan.
4. 当主语部分有实义动词 do 时 (以及do的其他形式时) ,作表语的动词不定式通常要省略to (即“前有do, 后无to”)。如：
What you should do is (to) open the door.
All I want to do now is (to) have a rest.
Practice
1. It’s bad for your eyes ________ (play) computer games too much.
2. His ambition is _____________ (become) a successful scientist when he graduates.
3. ___________ (enjoy) the convenience of digital payment, many senior citizens started to use smartphones.
4. What we can do is ____________ (ensure) that all students have access to a healthy diet.
5. It’s really kind of him ________ (let) us use his swimming pool.
to play
to become
To enjoy
(to) ensure
to let
(1) The next dish that the cook will prepare is Kung Pao Chicken. (attributive).
The next dish to be prepared by the cook is Kung Pao Chicken.
(2) The preparation of home-cooked meals is easy and enjoyable. (subject)
To prepare home-cooked meals is easy and enjoyable. / It is easy and enjoyable to prepare home-cooked meals.
(3) Her dream is that she will open a restaurant some day. (predicative)
Her dream is to open a restaurant some day.
Applying the rules
B1
(4) We will put the potatoes in the pot first in order that they will be cooked quickly. (adverbial of purpose)
We will put the potatoes in the pot first (in order) to cook them quickly.
(5) I consider the Soup of the Day as the best option on the menu. (object complement)
I consider the Soup of the Day to be the best option on the menu.
Applying the rules
Complete the article with the correct forms of the verbs in the brackets.
Located
to turn
to sit
painted
ranging
to invite
to be
to see
B2