以下就是小編整理的one that定語從句，一起來看看吧！
大學聯考中常常考查one和that作爲普通代詞的區別,還常與it進行區別.主要用法如下：
／one ／that三者均可用作代詞,指代前面提到的名詞.一般說來,it指代同名同物; one與that則指代同名異物.
I have lost my umbrella; I'm looking for it.（該句中it就是指前面的my umbrella）
I have lost my umbrella; I think I must buy one.（one在該句中表泛指,因爲my umbrella已經丟了）
The umbrella you bought is cheaper than that I bought.（替代詞that在該句中特指“the umbrella I bought”,以區別“the umbrella you bought”）
與that雖可用來指代同名異物,但one爲泛指,相當於a／an＋名詞; that爲特指,相當於the ＋名詞.所以one所指代的名詞的修飾語一般爲 a／an ／some ／any; that所指代的名詞的修飾語往往是the ／this ／that.
A chair made of steel is stronger than one made of wood.（該句中one可以換成a chair）
The water in the cup is hotter than that in the pot.（該句中that可以換成 the water）
只能代替可數名詞單數,代替可數名詞複數時用ones; that既可以代替不可數名詞也可以代替可數名詞單數,代替可數名詞複數時用 those.
I like this pen more than that one.（one代替可數名詞單數pen）
There were a few young people and some older ones in the house.（ones代替可數名詞複數people）
Mary's handwriting is far better than that of Peter.（that代替不可數名詞 handwriting）
These pictures are more beautiful than those.（those代替可數名詞複數 pictures）
既可代替事物,也可代替人,that只能代替事物而不能代替人.有時可以用the one或the ones代替that或those.
The one ／That on the table is mine.（該句中The one代替事物,並且也可以用That）
He is the teacher,the one who is loved by the students.（該句中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.（該句中the ones代替事物,並且也可以用those）
一般有前置修飾語,有時也可有後置修飾語或不用修飾語.而 that不能有前置修飾語,但可有後置修飾語.
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.
可以替代句中的不定式或從句等,充當形式主語或形式賓語與that均無此用法.
It is known to everybody that the moon travels around the earth once every month.
I found it hard to get on with her.
與that均可以替代上文全句的內容或部分內容,而one ／ones則不可以.
附：定語從句定語用來限定、修飾名詞或代詞的，是對名詞或代詞起修飾、限定作用的詞、短語(動詞不定式短語、動名詞短語和分詞短語)或句子，漢語中常用的表示。主要由形容詞擔任，此外，名詞，代詞，數詞，分詞，副詞，不定式以及介詞短語也可以來擔任，也可以由一個句子來擔任。單詞作定語時通常放在它所修飾的`詞之前，作前置定語。短語和從句作定語時則放在所修飾的詞之後，作後置定語。
定語從句是指在一個句子中作定語的句子，定語從句要放在所修飾的詞後。
如：1) The man who lives next to us is a policeman.
2) You must do everything that I do.
上面兩句中的man和everything是定語從句所修飾的詞，叫先行詞，定語從句放在先行詞的後面。
引導定語從句的詞有關係代詞that, which, who(賓格who, 所有格whose)和關係副詞where, when、why
關係詞常有三個作用：1、引導定語從句 2、代替先行詞 3、在定語從句中擔當一個成分
