如何判断英语句子中的主语谓语定语宾语等等成分

句子成分
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 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）
We will make them happy.（形容词） We found nobody in.( 副词 )
Please make yourself at home.介词短语） Don’t let him do that.（省to不定式）
His father advised him to teach the lazy boy a lesson.（带to不定式）
Don’t keep the lights burning.（现在分词） I’ll have my bike repaired.（过去分词）
主补：对主语的补充.
He was elected monitor.She was found singing in the next room.
He was advised to teach the lazy boy a lesson.
定语：修饰或限制名词或代词的词、词组或句子.
Ai Yanling is a chemistry teacher.（名词） He is our friend.（代词）
We belong to the third world.（数词） He was advised to teach the lazy boy a lesson.（形容词）
The man over there is my old friend.(副词) The woman with a baby in her arms is my sister.(介词)
The boys playing football are in Class 2.（现在分词）
The trees planted last year are growing well now.（过去分词）
I have an idea to do it well.（不定式）
You should do everything that I do.（定语从句）
状语：用来修饰v.,adj.,adv.,or 句子.表示时间、地点、原因、目的、结果、程度、条件、方式和让步.
（以下例句按上述顺序排列）
I will go there tomorrow.The meeting will be held in the meetingroom.
The meat went bad because of the hot weather.He studies hard to learn English well.
He didn’t study hard so that he failed in the exam.I like some of you very much.
If you study hard,you will pass the exam.He goes to school by bike.
Though he is young,he can do it well.
句子结构
简单句的五个基本句型
主语 ＋ 不及物动词 She came．/ My head aches.
主语 ＋ 及物动词 ＋宾语 She likes English.
主语 ＋ 系动词 ＋主语补语 She is happy．
主语 ＋ 双宾动词 ＋间接宾语 ＋直接宾语 She gave John a book．
She bought a book for me.
主语 ＋ 宾补动词 ＋ 宾语 ＋ 宾语补语 She makes her mother angry．
The teacher asked me to read the passage.
（ There +be There lies a book on the desk.）

我吃了一个红苹果
I ate a red apple.
I
我:主语，就是施加动作的人
ate
吃了：谓语，就是动作
a
一个：是冠词
red
红：定语，修饰宾语的
apple
苹果：动作施加的对象，宾语
主动句大都可照此分析。

主语通常是名词，代词，或者是名词性句子。谓语一般为动词，包括实义动词，系动词。定语通常修饰名词或代词，本身可由名词代词或介词短语等组成。你可以买一本语法书，结合例句来学习，这个东西还要靠平时的多练习。