老师，请讲一下代词 it, one, that, those 的用法问题。谢谢老师。

（语法网的有点难, 我看不懂）。

解答如下：

it,one, that those区别如下

【1】it指代同类同物，即前面提到的人或者事物，属于同一个人或者事物。

it代替同类同物

I have lost my umbrella; I'm looking for it.

（该句中it就是指前面的丢失那把伞）(同类同物）

Do you want the magazine? Yes,I want it.

 你想要这本杂志吗？是的，我要。

 He looked for his watch everywhere yesterday,but he couldn't find it anywher

昨天他到处寻找自己的手表，但他在哪儿都找不到。

I don't want to drink the tea.It is too hot.

我不想喝这茶，它太热了。

【2】one指代同类异物，即前面提到的同类但是不是同一个人或者同一个事物，表示一种泛指，即同类事物中任何一个，相当于不定冠词a/an+名词。

one代替同类，但是不是同一个事物

I have lost my umbrella; I think I must buy one.  （同类不同物）

（one在该句中表泛指, 这里不是指我丢失那把伞，相当于an  umbrella,）

I have lost my pen,I'm going to buy one.

我的钢笔丢了，我要去买一支。

I have a new coat and several old ones.

我有一件新大衣和几件旧的。

【3】that 也指代同类异物，但是特指，相当于定冠词the+名词。

The umbrella you bought is cheaper than that I bought.

（替代词that在该句中特指“the umbrella I bought”, 以区别“the umbrella you bought”）

【4】one只能代替单数可数名词表示泛指，可以带上前置定语，代替复数名词泛指可以用复数为ones。

I like this pen more than that one.

（one代替可数名词单数pen）

There were a few young people and some older ones in the house.

（ones代替可数名词复数people）

特别备注以下几点

(1)one前可用this，that修饰，但ones前不能用these或those修饰，除非one前有形容词修饰。

I prefer this one to that one.

我喜欢这个，而不喜欢那个。

These yellow ones are so small.I want those green ones.

这些黄的太小，我要那些绿的。

(2)one和ones前面不能用物主代词。

This is my apple and that's yours.(不说your one)

这是我的苹果，那是你的。

(3)one和ones前面有修饰词时，可以加冠词，有时the ones和those可互换使用，但要求后面有修饰语。

I don't like this pen.Show me a better one.

我不喜欢这支钢笔，再给我好一点的钢笔看一看。

【5】that能代替单数可数名词表示特指，可以带上后置定语，代替复数名词特指可以用复数为those(备注，还可以代替不可数名词单数)。

Mary's handwriting is far better than that of Peter.

（that代替不可数名词 handwriting）（代替可数名词单数特指）

These pictures are more beautiful than those.

（those代替可数名词复数 pictures）（代替可数名词复数，特指）

The water in the cup is hotter than that in the pot.

（该句中that可以换成 the water）（代替不可数名词）

特别备注以下几点

(1)that既可代替可数名词，又可代替不可数名词，常要求有后置定语，一般不指人。

The price of wheat is higher than that of rice.

小麦的价格比大米高。

The population of China is larger than that of Japan.

中国的人口比日本多。

(2)that one用来替代同类事物中特指的另一个，可与 that替换。

This story is not so interesting as the one/that we heard last night.

这个故事不如我们昨晚听到的那一个有趣。

(3) that可代替上文全句的内容，it和one则不能。

He will ask me to lend him some money and I  can't do that.

他要问我借点钱，可我不能借。

We see him when he comes to town,but that isn't often.

他进城时我们能见到他，但这种情况不常有。

【6】 one既可代替事物, 也可代替人, that只能代替事物而不能代替人。有时可以用the one或the ones代替that或those。

The one ／That on the table is mine.

（该句中The one代替事物, 并且也可以用That）

He is the teacher, the one who is loved by the students.

（该句中the one代替人, 不能用that）

He advised the farmers to choose the best seed-heads, the ones ／those that had the best color.

（该句中the ones代替事物, 并且也可以用those）

【7】one一般有前置修饰语, 有时也可有后置修饰语或不用修饰语。而 that不能有前置修饰语, 但可有后置修饰语。

Cook was a strict but good captain, one who took good care of his sailors.

The water in the well is cleaner than that in the river.

【8】it可以替代句中的不定式或从句等, 充当形式主语或形式宾语。one与that均无此用法。

A:it形式主语代替主语从句

It is known to everybody that the moon travels around the earth once every month.

B:it形式宾语代替真正宾语不定式

I found it hard to get on with her.

C:it形式主语代替真正主语动名词

It is hard work climbing mountains.

It is no use talking about this with him.

It is no use arguing with a drunk. 

跟一个醉汉争论是没有用处的。

D:it形式主语代替真正主语不定式for sb/of sb的复合结构

It is hard for him to make up his mind.

It was foolish of her to say such a thing.

【9】it与that均可以替代上文全句的内容或部分内容, 而one ／ones则不可以。

He has saved my life; I'll never forget it. 

（it代替第一分句）

Tom is painting his house. I am told he does it every four years. 

（it代替前面分句的部分内容painting his house）

Let's say we meet here at three o'clock. That ought to give you time to buy everything. 

（that代替前面表述的内容）

【10】those可用来替代可数名词的复数，表示特指。有时the ones和those可互换使用，常要求有后置定语。

 The students in our class work harder than those in their class.

 我们班的同学比他们班的同学学习更刻苦。