主语（subject）: 句子说明的人或事物。

the sun rises in the east. （名词） he likes dancing. （代词）

twenty years is a short time in history. (数词) seeing is believing. （动名词）

to see is to believe. （不定式） what he needs is a book. （主语从句）

it is very clear that the elephant is round and tall like a tree. （it形式主语，主语从句是真正主语）

谓语（predicate）: 说明主语的动作、状态和特征。

we study english. he is asleep.

表语（predicative）: 系动词之后的成分，表示主语的性质、状态和特征。

he is a teacher. （名词） seventy-four! you don’t look it. （代词）

five and five is ten. （数词） he is asleep. （形容词）

his father is in. （副词） the picture is on the wall. ( 介词短语)

my watch is gone / missing / lost. （形容词化的分词）

to wear a flower is to say “i’m poor, i can’t buy a ring. （不定式）

the question is whether they will come. （表语从句）

（常见的系动词有: be, sound（听起来）, look（看起来）, feel(摸起来，smell（闻起来）, taste（尝、吃起来）,

remain（保持，仍是）, feel（感觉） ...

it sounds a good idea. the sound sounds strange.

her voice sounds sweet. tom looks thin.

the food smells delicious. the food tastes good.

the door remains open. now i feel tired.

宾语：1）动作的承受者-----动宾

i like <?xml:namespace prefix = st1 />china. （名词） he hates you. （代词）

how many do you need? we need two. （数词）

we should help the old and the poor. i enjoy working with you. （动名词）

i hope to see you again. （不定式） did you write down what he said? （宾语从句）

2） 介词后的名词、代词和动名词-----介宾

are you afraid of the snake? under the snow, there are many rocks.

3） 双宾语-----间宾（指人）和直宾（指物）

he gave me a book yesterday. give the poor man some money.

宾补：对宾语的补充，全称为宾语补足语。

we elected him monitor. （名词） we all think it a pity that she didn’t come here. （名）