译林版高中英语选择性必修第一册Unit 1 Food matters Grammar and usage动词不定式教学课件（共21张）

(共21张PPT)
To-infinitives
动词不定式
One of the most popular winter sports is skiing. Cross-country skiing requires skiers to use their own strength and movement to get across an area that is covered with snow. Many people enjoy cross-country skiing because it allows them to go at a pace that is slow enough to explore the countryside. It is also a good way to get some exercise.
Other people prefer to ski down a hill because they think it is more thrilling. Downhill skiing involves riding a mechanical lift up a hill or mountain. From there, skiers glide down. Downhill skiing can be dangerous. Some people worry about getting injured. To control one’s speed properly takes a lot of practice.
A gerund can be used as the subject of a sentence or the object of a verb. A gerund can also be used as the object of a preposition.
Skiing requires a lot of strength.
Many people enjoy skiing.
subject
object of the verb
Some people worry about getting injured.
object of the preposition
Like gerunds, infinitives can also be used as the subject
of a sentence or the object of a verb, but it is not common to use an infinitive as the subject.
Some people prefer to ski down a hill.
To control one’s speed properly takes a lot of practice.
object of the verb
subject
Have you ever tried snowboarding It is a winter sport that was inspired by skateboarding, surfing, and skiing. It involves going down a slope with a snowboard attached to the rider’s feet. Snowboarding was developed in the United States in the 1960s. In the 1970s snowboarders began to go to traditional ski resorts. Many skiers didn’t appreciate sharing “their” mountain with snowboarders, but snowboarding kept growing in popularity. By the 1990s, almost all ski resorts had agreed to accept both skiers and snowboarders. In the late 1990s, the International Olympic Committee decided to make snowboarding an official sport of the Winter Olympics.
Gerunds can be used as the objects of certain verbs.
Many skiers didn’t appreciate sharing the mountain.
Snowboarding kept growing in popularity.
enjoy quit (give up) avoid
appreciate finish (get through) consider
postpone discuss mind
delay mention suggest
keep (keep on)
Some verbs are followed immediately by infintives.
Ski resorts agreed to accept both skiers and snowboarders.
The committee decided to make snowboarding an official sport.
want to refuse to intend to
hope to need to promise to
plan to offer to seem to
like to agree to pretend to
decide to appear to ask to
PRACTICE 1
Complete each sentence with a gerund or infinitive.
1. Both skiing and snowboarding can be dangerous. Some people are scared of (get) __________ injured.
2. Tatiana enjoys (competing) ___________ in races.
3. She hopes (participate) _____________ in the Winter Olympics next year.
4. She needs (practice) ______________ every day.
5. Tatiana’s coach has agreed (work) ___________ with her every day until it’s time for the Olympic try-outs.
6. The coach intends (see) __________ Tatiana win a medal.
getting
competing
to participate
to practice
to work
to see
Some verbs can be followed by either an infinitive or a gerund with no difference in meaning.
Snowboarders began to go to traditional ski resorts.
same meaning
Snowboarders began going to traditional ski resorts.
Some verbs can be followed by either an infinitive or a gerund, but the meaning is different.
John stopped snowboarding after he hurt his knee.
Sometimes on drives through mountains, Ella stops to snowboard.
(stop + gerund = stop an activity)
(stop + infinitive = stop one activity in order to start another. Ella stops driving in order to snowboard)
Scott, Mazzen, and Ray went camping in the mountains. They had fun spending time together, but they had trouble hiking up the mountain. They had to use snowshoes to get to their destination. Snowshoes look like big paddles that people attach to the bottom of their shoes in order to walk on top of snow. Without the snowshoes, their feet might sink deep into the snow. This can be very dangerous, especially in deep snow. It is difficult to get out of very high snow.
Go is followed by a gerund in some idiomatic expressions, usually to express recreational activities.
They decided to go camping.
They went hiking in their snowshoes.
go biking go fishing go shopping
go camping go hiking go skating
go canoeing go jogging go skiing
go dancing go running go swimming
-ing form follows certain special expressions.
They were having a good time using their snowshoes.
They were having fun using their snowshoes.
have a good time
have fun
+
verb -ing
-ing form follows certain special expressions.
They had a hard time walking up the mountain.
have trouble/difficulty
have a hard time
have a difficult time
+
-ing
They had trouble walking up the mountain.
An infinitive phrase is often used with it as the subject of a sentence.
It is difficult to hike in the snow.
It is fun to try new sports.
It isn’t necessary to spend a lot of money on sports.
PRACTICE 2
1. What winter activities do you enjoy
2. Which winter sports do you want to try
3. Have you tried ice skating
4. Would you prefer to go skiing or snowboarding
5. Have you ever had a hard time learning something new
6. What sports are difficult to do
Are you ready to try skiing or snowboarding Being prepared for the cold winter conditions is very important. Before you can begin, you need to be dressed in proper gear. You need a good ski bib or ski pants and a jacket. A good ski suit should
be flexible enough to allow you to move freely. You also need a good pair of gloves that are thick, but they should not be too stiff to move. Finally, you’ll need a pair of ski goggles in order to protect your eyes and a helmet to protect your head.
In order to is used to express purpose. It answers the question “Why ” In order is often omitted.
You need a good pair of goggles to protect your eyes.
You need a good pair of goggles in order to protect your eyes.
Enough can be followed by an infinitive. Enough follows an adjective and usually precedes a noun. Too can also be followed by an adjective + infinitive. It implies a negative result.
Your gloves should be flexible enough to allow you to move your fingers.
It is too cold to go skiing without proper winter gear.
enough + noun
You need enough gear to stay warm.
adjective + enough
too + adjective
Passive gerunds use being + past participle. Passive infinitives use to be + past participle.
You need to be dressed in proper gear.
Being prepared for the cold winter conditions is very important.
passive gerund
passive infinitive
PRACTICE 3
Check Your Knowledge
1. Isabel went (skiing, to ski) with her friends last weekend.
2. She had a good time (catching up, to catch up) with her friends.
3. She was (too tired, tired enough) to ski again the next day.
4. I’m not (enough experience, experienced enough) to ski on
advanced trails.
5. I need to take some lessons (in order to improve , for improving)
my skills.
6. It is important (being prepared, to be prepared) for emergency
situations.