代词是代替名词的词, 按其意义、特征及其在句中的作用分为：人称代词、物主代词、指示代词、反身代词、相互代词、疑问代词、不定代词和关系代词等。
1)人称代词的人称、数和格，如下表所示。
单数：
主格：I/you/he/she/it
宾格：me/you/him/her/it
复数：
主格：we/you/they
宾格：us/you/them
2)人称代词有主格和宾格之分。通常主格作主语，宾格作宾语。如：
i like table tennis. (作主语)
do you know him?(作宾语)
3)人称代词还可作表语。作表语时用宾格。如：
---whos is knocking at the door?
---it’s me.
4)人称代词在than之后与其他人或事物进行比较时，用主格和宾格都可以。如：
he is older than me.
he is older than i am.
2 物主代词
1)表示所有关系的代词叫物主代词。物主代词分形容词性物主代词和名词性。
形容词性物主代词：my/your/his/her/its/our/your/their
名词性物主代词：mine/yours/his/hers/its/ours/yours/theirs
2)形容词性物主代词的作用相当于形容词，可在句中作定语。例如：
our teacher is coming to see us.
this is her pencil-box.
3)名词性物主代词的作用相当于名词，在句中可用作主语、宾语和表语。
our school is here, and theirs is there.(作主语)
--- is this english-book yours? (作表语)
--- no. mine is in my bag.
i've already finished my homework. have you finished yours? (作宾语)
3 指示代词
指示代词包括：this，that，these，those。
1) this和these一般用来指在时间或空间上较近的事物或人，that和those
则指时间和空间上较远的事物或人，例如：
this is a pen and that is a pencil.
we are busy these days.
in those days the workers had a hard time.
2)有时that和those指前面讲到过的事物，this 和these则是指下面将要讲到的事物，例如：
i had a cold. that's why i didn't come.
what i want to say is this ; pronunciation is very important in learning english.
3)有时为了避免重复提到的名词，常可用that或those代替，例如：
television sets made in beijing are just as good as those made in shanghai.
4)this 在电话用语中代表自己，that 则代表对方。例如：
hello! this is mary. is that jack speaking?
4 反身代词
英语中用来表示"我自己"，"你自己"，"他自己"，"我们自己"，"你们自己"
等意义的代词称为反身代词，也有人称之为自身代名词。
第一人称单数：myself 复数：ourselves
第二人称单数：yourself 复数：yourselves
第三人称单数：himself/herself/itself 复数：themselves
反身代词可以在句中作宾语，表语，同位语。
1)作宾语，表示动作的承受者就是动作的发出者，主语和宾语指同一个人
或一些人。
he called himself a writer.
would you please express yourself in english?
2)作表语。
it doesn't matter.i'll be myself soon.
the girl in the news is myself.
3)作主语或宾语的同位语，表示亲自或本人。
i myself washed the clothes.(=i washed the clothes myself.)(作主语同位语)
you should ask the teacher himself.(作宾语同位语)
不定代词
不是指明代替任何特定名词的代词叫做不定代词，在句中可作主语、表语、宾语和定语。现将几个常用的不定代词举例说明如下：
1 some与any的区别
1.some多用于肯定句，表示“一些，几个”作形容词时，后面可以接①不可数名词+单数动词;②可数名词+复数动词。
look! some of the students are cleaning the library.
some rice in the bag has been sold out.
2.any多用于疑问句、条件句和否定句中，表示“一些，任何”用作形容词时，后面可以接①不可数名词+单数动词;②可数名词+复数动词。
if you have any questions, please ask me.
there isn't any orange in the bottle.
have you got any tea?
3.any和some也可以作代词用，表示“一些”。any多用于疑问句或否定句中，some多用于肯定句中。
how many people can you see in the picture?
i can't see any.
if you have no money, i'll lend you some.
注意：与some, any结合的词如something, somebody, someone, anything, anyone, anybody在肯定句、否定句、疑问句、条件句中的用法，大致和some, any的用法相同。
2 few, a few, little, a little在用法上的区别
①用作形容词：
i'm going to buy a few apples.
he can speak only a little chinese.
there is only a little milk in the glass.
he has few friends.
they had little money with them.
②a little和little也可以用作副词，a little表示“有点，稍微”，little表示“很少”。
i'm a little hungry. (修饰形容词hungry)
let him sleep a little. (修饰动词sleep)
mary, go a little faster, please. (修饰副词比较级)
she slept very little last night.
3 other, the other, another, others, the others的区别
another 代名词，单数，另一个
others 代名词，复数，别人，其他人
another (boy) 形容词，单数，另一个(男孩)
other (boys) 形容词，复数，其他男孩
the other 另一个
the others 其余那些人、物
the other (boy) 另一个男孩
the other (boys) 其余那些男孩
①other可以作形容词用，后面可以跟单数或复数名词，意思是“其他的、别的”。
where are his other books?
i haven't any other books except this one.
②other也可以用作代词，与冠词the连用构成“the other”，表示两个人或物中的“另一个”。常与one搭配构成“one ..., the other ...”句型。
he has two brothers. one is 10 years old , the other is 5 years old.
she held a ruler in one hand and an exercise-book in the other.
③other作代词用时，可以有复数“others”，泛指“另外的人或物”。常与some搭配构成“some ...., others ...”句型。
some went to the cinema, others went swimming.
this coat is too large. show me some others, please.
④“the others”表示特指某范围内的“其他的人或物”。
we got home by 4 o'clock, but the others didn't get back until 8 o'clock.
in our class only tom is english, the others are chinese.
⑤another可以作形容词用，修饰后面的名词，意为“另一个”，还可以跟代词one.
you can see another ship in the sea, can't you?
mary doesn't want to buy this skirt. would you please show her another one?
⑥another也可以作代词用，表示“另一个”。
i'm still hungry after i've had this cake. please give me another.
4 every与each的区别
the teacher gave a toy to each child.
each ball has a different colour.
当我们说each child, each student或each teacher时，我们想到的是一个人的情况。而当我们说every child和every student时，我们想到的是全体的情况，every的意思与all接近，表示他们都如此。
every student loves the english teacher. = all students love the english teacher.
every child likes playing. = all children like playing.
5 all和both的用法
①all指三者以上，或不可数的东西。谓语动词既可以用单数，也可以用作复数。在句中作主语、表语、宾语、同位语和定语。
all of us like mr pope. 我们都喜欢pope先生。(作主语)
= we all like mr pope. (作同位语)
all the water has been used up. (作主语)
that's all for today. (作表语)
why not eat all (of) the fish? (作宾语)
all the leaders are here. (作定语)
②both作代词。
a.与其他名词或代词并列出现，表示“两个都”。
lucy and lily both agree with us.
they both passed on their sticks at the same time.
how are your parents? they're both fine.
b.与“of +代词(或名词)”连用，表示“两者都”。
both of them came to see mary.
both of the books are very interesting.
c.单独使用，表示“两者(都)”。
michael has two sons. both are clever.
i don't know which book is the better, i shall read both.
③both用作形容词，放在名词之前，修饰该名词，表示“两者都”。
both his younger sisters are our classmates.
there are tall trees on both sides of the street.
相互代词
表示相互关系的代词叫做相互代词。相互代词有each other 和one another两种形 式。在当代英语中，each other和one another没有什么区别。相互代词可在句中作宾语，定语。作定语用时，相互代词用所有格形式。
we should learn from each other / one another. (作宾语)
do you often write to each other / one another? (作宾语)
we often borrow each other's / one another's books. (作定语)
the students corrected each other's / one another's mistakes in their homework.(作定语)
疑问代词
疑问代词有who，whom，whose，what和which等。疑问代词用于特殊疑
问句中，一般都放在句首，并在句子中作为某一句子成分。例如：
who is going to come here tomorrow? (作主语)
what is that? (作表语)
whose umbrella is this? (作定语)
whom are you waiting for? (作宾语)
关系代词
关系代词是一种引导从句并起连接主句和从句作用的代词。关系代词有 who, whose, whom, that, which. 它们在句中可用作主语,表语,宾语,定语. 在主句中,它们还代表着从句所修饰的那个名词或代词。例如：
i hate people who talk much but do little.
i’m looking at the photograph which you sent me with your letter.
with the money that he had saved, he went on with his studies.
do you know the lady who is interviewing our headmaster?