名词在句子中承担什么功能，由其在句子中得句子成分来决定。词性分为名词、动词、形容词、副词等实词以及连词、介词、感叹词、冠词等虚词；句子按其成分分主语、宾语、谓语、定语、状语及补语等。我们看名词可以作哪些句子成分：
①作主语。如
A few boys are playing under the tree.
②作宾语。如
I saw a few boys playing under the tree.
③作表语。如
He is a handsome boy.
④作定语。一个名词作定语修饰另一个名词，常表示材料、用途和内容等。如
arms race 、air raid、alarm clock等
The *ernment is determined to put
a brake on public spending.
⑤作补语。如
We might call it a mistake in tactics.
Tom is considered a good student.
⑥作状语。如
Tom works day and night.
⑦作同位语。如
We students must work hard.
⑧作独立成分。如
Ladies and gentlemen,please take your
seats.
