限定词，顾名思义，是用来限定名词的一类词。我们知道，名词指代人、物、事、时、地、情感、概念等实体或抽象事物的词，但是在句子中，某一名词是特指，还是类指，是确定数量，还是不确定数量，这些都要靠“限定词”来决定。

因此，限定词是在名词词组中对名词中心词起特指、类指以及表示确定数量和非确定数量等限定作用的词类。

英语的限定词有以下几类：

1.冠词：定冠词、不定冠词、零冠词

The red book is mine.

There is a pen and  an apple on the desk.   

Time is money.

2.物主限定词：my, your, his, her, our, your, their, one's, its. 

My bike is broken.

3.名词属格：John's, my friend's. 

John's brother will go to school next year.

4.指示限定词：this, that, these, those, such

This story is very interesting.

Such novels are worth reading.

5.关系限定词：whose, which

The children whose parents died are not homeless any more.

These questions are all on philosophy, about which subject I know little.

6.疑问限定词：what, which, whose

Whose books are these?

Which restaurant is your favourite?

What films do you like watching?

7.不定限定词：no, some, any, each, every, enough, either, neither, all, both, half, several, many, much, (a) few, (a) little, other, another. 

There are some books on the desk.

Do you have enough money?

8.基数词和序数词倍数词和分数词

There are three pens in my bag.

The first answer is correct.

9.量词：a lot of, lots of, plenty of, a great /good deal of, a large of, a small amount of, a quantity of, a great/ large/ good number of等。

We prepared plenty of food and drinks for the party.

限定词虽然属于“封闭词类”，但种类繁多，使用频繁，我们需要分类记忆，灵活运用。