不定式

一 不定式的时态意义

1．一般式：表示不定式动作与谓语动词的动作同时发生或在其后发生。

《剑桥雅思真题7》Test B Passage 1

We ask all campers to show due care and consideration whilst staying here and to observe the following camp rules.

我们要求所有的露营者在这里逗留期间表现出适当的关心和考虑，并遵守以下露营规则。

2．进行式：表示不定式所表达的动作在谓语动词所表达的动作发生之前。

《剑桥雅思真题8》Test B Section 1

If you don't seem to be getting anywhere, you can get help.

如果你看起来毫无进展，你可以寻求帮助。

3．完成式：表示不定式所表达的动作在谓语动词所表达的动作之前发生。

《剑桥雅思真题7》Test 4 Passage 1

And they are known to have used wooden pulleys, which could have been made strong enough to bear the weight of massive blocks of stone.

人们知道他们使用的是木制滑轮，这种滑轮可以被制作得足够结实，足以承受巨大石块的重量。

4．完成进行式：表示不定式所表达的动作在谓语动词所表达的动作发生之前一直在进行，其形式为to have been doing。

二 不定式的语态

1．当逻辑主语是不定式所表达的动作的执行者时，不定式用主动语态。

《剑桥雅思真题7》Test B section 1

You use your phone to keep family and friends in touch.

你用手机和家人及朋友保持联系。

2．当逻辑主语是不定式所表达的动作的承受者时，不定式用被动语态。

《剑桥雅思真题7》Test 1 Passage 3

In a preliminary talk, the teacher introduces them to the material to be covered, but does not ‘teach' it.

在一次初步的谈话中，老师向他们介绍了要学习的内容，但没有“教授”。

三 不定式的语法功能

1．作主语。

（1）直接作主语。

《剑桥雅思真题10》Test 1 Writing Sample 2

To punish a very young child is both wrong and foolish, as an infant will not understand what is happening or why he or she is being punished.

惩罚一个年幼的孩子是错误的，也是愚蠢的，因为婴儿不会明白发生了什么或为什么他或她会受到惩罚。

（2）用it作形式主语，作真正主语的动词不定式置于句末。

《剑桥雅思真题7》Test 2 Passage 3

It made sense to improve the paths by building steps, handrails and footbridges.

通过建造台阶、扶手和人行天桥来改善道路是有意义的。

2．作主语补足语。

《剑桥雅思真题7》Test A Passage 1

All employees are required to carry an I.D. card.

所有员工都必须携带身份证。

3．作表语。

《剑桥雅思真题7》Test 4 Passage 1

His idea is to build the arches horizontally, then lift them into place using kites.

他的想法是在水平方向建造拱门，然后用风筝把它们拉到合适的位置。

《剑桥雅思真题7》Test 1 Passage 3

The teacher's task is to assist the students to apply what they have learned paraconsciously, and in doing so to make it easily accessible to consciousness.

教师的任务是帮助学生将他们所学的知识应用到辅助学习中，并使其易于被意识所理解。

4．作同位语。

《剑桥雅思真题7》Test 1 Passage 1

Before this was discovered, engineers had already built instruments to exploit the principle, for example to measure the depth of the sea under a ship.

在这一发现之前，工程师们已经建造了仪器来利用这一原理，例如测量船下的海洋深度。

5．作宾语。

（1）形式为动词+to do。

《剑桥雅思真题5》Test 3 Section 1

You do decide to make an application.

你确实决定申请。

（2）it作形式宾语，真实宾语为其后的动词不定式。

《剑桥雅思真题9》Test 2 Passage 1

Children experiencing these disorders find it difficult to screen out unimportant information.

患有这些疾病的儿童发现很难筛选出无关紧要的信息。

6．作宾语补足语。

《剑桥雅思真题7》Test 2 Passage 1

Clearly, Japanese carpenters of the day knew a few tricks about allowing a building to sway and settle itself rather than fight nature's forces.

显然，当时的日本木匠知道一些让建筑摇摆和稳定的技巧，而不是对抗自然的力量。

7．作定语。

《剑桥雅思真题7》Test 1 Passage 1

Bats are not the only creatures to face this difficulty today.

蝙蝠不是今天唯一面临这种困难的生物。

8．作状语。

《剑桥雅思真题7》Test 2 Passage 3

An improvement of the road network was considered necessary to ensure the import and export of goods to the district.

认为有必要改善公路网，以确保向该地区进出口货物。

《剑桥雅思真题11》Test 1 Passage 3

To avoid such a scenario, Lunt says Angels project would have to operate at half strength.

为了避免这种情况，伦特说，天使项目必须以一半的力量运作。

《剑桥雅思真题11》Test 2 Passage 2

To feed the people, even more land had to be cleared.

为了养活人民，更多的土地必须被清理干净。

四 wh-疑问词+to do（不定式）

这是常见结构，比如：I don't know what to say/which one to eat/how to achieve/who to speak to/when to start/where to live/why to go/whether to purchase it。

1．作主语。

What to offer has not been decided .

提供什么还没有决定。

2．作表语。

《剑桥雅思真题13》Test 4 Passage 3

The only question is how to achieve it.

唯一的问题是如何实现它。

3．作宾语。

《剑桥雅思真题7》Test 1 Passage 1

Two factors: people have figured out how to use water more efficiently, and communities are rethinking their priorities for water use.

有两个因素：人们已经知道如何更有效地利用水资源，社区正在重新考虑用水的优先事项。

4．作同位语。

《剑桥雅思真题7》Test 1 Passage 1

Bats have an engineering problem: how to find their way and find their prey in the absence of light.

蝙蝠有一个工程问题：如何在没有光线的情况下找到它们的方向和猎物。

5．作定语。

The card with which to open the door has been lost.

用来开门的那张卡丢了。

五 省略不定式符号to的情况

1．help后面接带to或不带to的不定式都可以。

《剑桥雅思真题12》Test 5 Passage 3

The course will help them to detect cases of arson.

该课程将帮助他们发现纵火案件。

《剑桥雅思真题7》Test 1 Passage 1

They hunt at night, and cannot use light to help them find prey and avoid obstacles.

它们在夜间捕猎，无法利用光线来帮助它们寻找猎物和躲避障碍物。

2．do+(everything/nothing/anything)后面接but或except时，其后面可省略to，或不省略。

《剑桥雅思真题7》Test 3 Passage 1

They do everything but watch television.

除了看电视，他们什么都做。