替代詞，就是在日常學習中所用的代詞或量詞。針對學生們常見的一些練習和考題，總結(jié)了一下幾種特殊替代用法：
it 在句中作形式主語或形式賓語的替代用法
1. it作形式主語可以代替句中的動詞不定式、動詞-ing分詞或一個句子。
It is important for us to learn English well. (it替代不定式to learn English)
It is no use making such an apology to us Chinese. ( It 替代動詞-ing分詞 making such an apology)
It is happy for her parents that she is well now. (it 替代句子that she is well now)
2. it作形式賓語可以代替句中的動詞不定式，此時句中的謂語事由某些特殊動詞 (如：find, think, feel等)充當?shù)摹?BR> I find it impossible to finish so much work in such a short time. (it 替代不定式to finish so much work)
that this在句中的替代用法
1. that
A: I’m going to wear my new jeans to her party.
B: You can’t do that. (that替代to wear my new jeans to her party這一事情)
2. this
this 在介紹某人或某物時，指的是靠近自己的一方。
A: Hi, Mr. Smith, This is my friend, Bill.
B: Nice to meet you, Bill.
C: Nice to meet you, Mr. Smith.
This 在電話用語中指的是自己。
A: Hello, may I speak to Miss Li?
B: This is Miss Li speaking. (我就是李女士)
which、that 、who、whom在定語從句中的替代用法
1. which 在句中放指物的先行詞后或整個句子后，引導限定性定語從句或非限定性定語從句。
She said I was lazy, which isn’t true.( which替代句子 She said I was lazy)
This is the pen which was bought by my father. (which替代的是 the pen)
2. that在句中放先行詞后，引導限定性定語從句。既可指物，也可指人。
The book that she borrowed from the library was lost. ( that替代的是The book)
The man that with a knife in his hand is a murderer. (that替代的是The man )
it 在句中作形式主語或形式賓語的替代用法
1. it作形式主語可以代替句中的動詞不定式、動詞-ing分詞或一個句子。
It is important for us to learn English well. (it替代不定式to learn English)
It is no use making such an apology to us Chinese. ( It 替代動詞-ing分詞 making such an apology)
It is happy for her parents that she is well now. (it 替代句子that she is well now)
2. it作形式賓語可以代替句中的動詞不定式，此時句中的謂語事由某些特殊動詞 (如：find, think, feel等)充當?shù)摹?BR> I find it impossible to finish so much work in such a short time. (it 替代不定式to finish so much work)
that this在句中的替代用法
1. that
A: I’m going to wear my new jeans to her party.
B: You can’t do that. (that替代to wear my new jeans to her party這一事情)
2. this
this 在介紹某人或某物時，指的是靠近自己的一方。
A: Hi, Mr. Smith, This is my friend, Bill.
B: Nice to meet you, Bill.
C: Nice to meet you, Mr. Smith.
This 在電話用語中指的是自己。
A: Hello, may I speak to Miss Li?
B: This is Miss Li speaking. (我就是李女士)
which、that 、who、whom在定語從句中的替代用法
1. which 在句中放指物的先行詞后或整個句子后，引導限定性定語從句或非限定性定語從句。
She said I was lazy, which isn’t true.( which替代句子 She said I was lazy)
This is the pen which was bought by my father. (which替代的是 the pen)
2. that在句中放先行詞后，引導限定性定語從句。既可指物，也可指人。
The book that she borrowed from the library was lost. ( that替代的是The book)
The man that with a knife in his hand is a murderer. (that替代的是The man )