4.All, both和each和含有every的复合代词用在否定句中只表示部分否定。

例：Not all the students have been to the Austrlia.

　　 She can’t work out both of the difficult problems.

Everybody cannot work out the problem.

her,none和含有no的复合代词表示全部否定。

例:None of us can answer the question.

Neither of the questions is right.

3.many, few和both用于可数名词，表示复数概念。

2.不定代词还可作定语。当作定语时，应该注意其所修饰的名词是可数还是不可数，以确定这个名词用单数还是复数。

例:Much has been done to fight pollution；each of them has got a present.

1.不定代词可作主语，当作主语时，要明确这一不定代词究竟是单数还是复数，以确定它和谓语动词在人和数的一致。

第二节 实战演练

(三)it作形式主语和形式宾语

it作形式主语和形式宾语是为了使句子平衡，而把真正的主语或宾语置于句子后面。例如： 　　 　　I found it interesting to study English.

　 It is of great help to master a foreign language.

3. 代替有生命但不能或不必分阴阳性的东西(包括婴儿)。例如：

　 The baby cried because it was hungry.

　 Someone is knocking at the door, who can it be?

(二)用作强调句，构成强调结构

句型结构：It is(was)+强调部分+that。例如：

　 It was last night that they left for H.K.

　 It was I that(who) his sister in the park yesterday.

It rains continually in the south in June. 　　　 It is a half hour’s walk to the factory.

2. 指代上文中提到的无生命的东西。例如：

　 Where is my notebook? It was here just now.

　 There is air all around us, but we cannot see it.

不是指明代替任何特定名词的代词叫不定代词。常见的不定代词有all, both, each, every, some, any, many, much, (a)few, (a)little, one, ones, either, neither, other, another, no, none以及含有some-, any-, no-等的合成代词(如：anybody, something, no one)。这些不定代词大多可以代替名词，在句子中作主语、宾语、表语或定语。但none和由some, any, no, every 构成的复合不定代词(如somebody等)只能作主语、宾语和表语。而every和no只能作定语。

3．Whose 用于明确所有者。whom 在口语中，多为 who 代替。