一、one作代词的用法 1.one替代由可数名词所表示的一类人或事物中的任何一个,即泛指中的强调.这时,替代词one前面不可加任何限定词.例如: 1)I hope there are enough glasses for each guest to have one.(NMET'95) 2)A color TV set made in Japan costs more than one made in China. 3)-Who can lend me a Chinese-English dictionary? -I have one. 2.one用来替代特指的同一类人或事物的可数名词时,其前面必须加上限定词(如a,the, this, that等)、物主代词或形容词加以修饰.例如: 1)If you don't like this blue coat, you can buy a black one. 2)I don't want the book on the shelf, I want this one on the desk. 3)Your old bike is white, while my old one is black. 3.one在定语从句中作先行词替代特指的同一类人或事物时,其前面必须用定冠词the限定,但不可用that替换.如果先行词为"one of...",其关系代词在定语从句中作主语,从句中的谓语动词常用复数形式.例如: 1)This farm is the one that we visited last summer.(句中the one代替this farm,作先行词,不可用that替代) 2)This is one of the highest buildings that have been built in our city recently. 3)Zhang Lei is the very one of the students who has been praised at the meeting. 4.one的复数形式为ones,作替代词时,只可替代同一类人或事物的复数名词,其前面必须有限定词,如the, some, all等修饰.但不能用数词或many修饰.例如: 1)Mr. Zhang gave the textbooks to the pupils except the ones who had already taken them.(句中the ones可用those替代)(MET92) 2)I don't want to buy these small pears; I want some large ones. 3)She wants to buy some new clothes and throw away all her old ones. 5.one在句中不可替代不可数名词.在句中如果出现了同一个不可数名词时,则需要重复前一个名词,或者省略那个名词.例如: 1)I prefer black coffee to white (coffee) .(white coffee中的coffee可省略也可不省,但不可用one替代coffee) 2)Folk music is the music that I like most.(不可用the one替代the music) 二、it作替代词的用法 1.it用来替代前面提到的同一事物时,被替代的名词可以是可数名词,也可以是不可数名词.例如: 1)We are studying in a school with trees all around it.(it替代可数名词school) 2)-Have you still kept your old furniture? -No,I have sold it.(it替代不可数名词furniture) 2.it可以替代英语句式中的不定式(短语)、动名词(短语)或从句,在句中作形式主语或形式宾语.例如: 1)It is a great surprise to meet you here.(It替代不定式短语to meet you here) 2)I think it is no good parents doing anything for their children.(it替代动名词的复合结构parents doing anything for短语) 3)We found it impossible that they could complete the task in two hours.(it替代that they could...从句) 3.it可以替代前面的某一名词或整个句子的内容.这时,可用that替换,也可以改为非限制性定语从句.有时it可以前置替代,用以代替后面整个句子的内容.这时,不可用that替换.例如: 1)He said he had never met her,and it is not true.(it替代前面整个句子He said...) 2)I hate it when people talk with their mouths full.(it代替后面整个句子when people talk with...)(NMET'98) 三、that作替代词的用法 1.that用来替代前面提到的特指的事物,所代替的名词可以是可数名词,也可以是不可数名词.代替可数名词可以用the one替换.但其前面不可用任何限定词修饰.例如: 1)The population of China is larger than that of Japan.(that代替不可数名词population,不可用the one替换) 2)The headteacher in your class is younger and more active than that in theirs.(that代替可数名词headteacher,可用the one替换) 2.that在并列分句中,可以替代前面某一个名词或整个句子内容,这时,可用it替换,也可改为非限制性定语从句.例如: 1)She heard a terrible noise,and that brought her heart into her mouth.(that替代前面的名词noise) 2)They said they had discussed the problem,and that (=it) was impossible.(that替代前面整个并列分句They said...) 3.that在定语从句中,可作关系代词,代替某个先行词(人或物).例如: 1)The lady that came to our class is from Australia.(that指代先行词lady) 2)A clock is a machine that tells people the time.(that指代先行词machine) 4.that的复数形式为those,只可替代可数名词复数,在句中相当于the ones.例如: 1)The nights there in summer are shorter than those in winter.(those替代nights,可用the ones替换) 2)The students who do best in the exam are not always those with the best brains.(those替代students,可用the ones替换) 本文来源：https://www.wddqw.com/doc/bba3811f50e79b89680203d8ce2f0066f433640a.html