代词（that, it，one等的区别）

代词one, it，that的用法在历届高考题中出现的频率较高，是高考的热点之一。笔者结合自己的教学实践在此谈谈它们的一些具体用法，希望能对同学们有一定的帮助。

笼统地说，it指代的是同类同物，that指代的是同类异物，one指的是上下文中提到的同类事物中的一个。以下是具体的区别：

1.one, it, that常常用来代替或避免重复某个名词。例如：

①I'm looking for a flat. I'd really like one with a garden.

②-Where did you find your watch? - I find it in our classroom.

③The population of China is larger than that of any other country.

2.one可指人或物，只替代单数可数名词，复数用ones. One是泛指，但有限定修饰语，如the, this, that…修饰就变成了特指。如：

①One must do one's duty.

②Mary has a red pencil and Jane has a blue one.

③The new designs are much better than the old ones.

3.that只指物，不指人，可替代可数名词或不可数名词，具有“特指”性质。指的是同类事物中的另一样东西，即同类异物。如：The library of our school is bigger than that of yours.(that代替的是另一个图书馆。)

4．One 和that 在代替可数名词时，如果没有前置定语只有后置定语时，the one 和that可互换。但该名词如有前置定语，则只能用the one,而不能用that。简单的说，就是one相当于an/a+名词，that相当于the+名词。例如：

①I will take the seat next to the one(=that)by the window.我就坐窗口的那个座位旁边。

②I prefer the large box to the small one.(one 不可用that替换 )。

5．That的复数形式those代替可数名词的复数。可指人或物，一般后面跟修饰语。如：

①Today's cellphones are smaller than those(=the ones)used in the past.

②The students who do best in exam are not always those(=the ones) with the best brains.

6.the one(ones)或 that ,those 指代某一名词做定语从句的先行词时，其关系代词which在that之后，which不能省略，而在the one、ones 之后,which可省略。如：

①Their problem today is somewhat similar to that which they faced many years ago.

7.代替不可数名词时，应该用that。如：The equipment is different from that.

8.it代替上文所提到的名词时，是指同类事物中的同一样东西，即同类事物。如：I have lost my pen. I'm looking for it.

9.it和that可代替前面整个句子的意思，而one却不能；that可引导一个限定性定语从句，代替某个先行词（单复数名词均可），it和one则不能；it可代替不定式、动名词或从句，用作形式主语或形式宾语，也可用于强调句型中，而one和that则不能。