句子成分（9个）：主，谓，宾，定，状，补，表，同位，插入●主语：句子的核心主体，通常位于谓语动词之前。
常做主语的有名词、代词、主语从句、V-ing、To do五种1.名词：Computers are widely used in almost all fields. 电脑在各个领域都被广泛使用beused to do /in+2.代词：We live in peacetime. 我们生活在和平年代It 作形式主语.：It 本身并没有实际意义，只是满足语法上的需求。
①It +is/was+adj./n. (+for+sb.)+to do sth.Eg: It is right to give up smoking. 戒烟是对的It is important for you to study hard. 对你来说努力学习很重要It is raining outside. 现在外面正在下雨It is April.21st. It is Sunday.-Who’s that/it? –It is me. 是谁？是我。
②it+v.(s/ed)+to do sth.Eg: It seems a pity to waste food. 浪费这些食物真可惜:It took me 1 hour to finish my homework. 做作业花费我1小时时间it+takes(took)+sb+一段时间+to do sth. 做某事花费某人多长时间③从句it+v.+thateg：It is said that the tickets were sold out. 据说票都卖完了在这里it只是形式上的主语，真正的主语在that后面3.一句话：Whether we will go to school tomorrow is undecided. 我们明天是否上课还未确定4.V-ing: Talking mends no holes. 空谈无济于事5.To do：To protect the environment is everybody’s business.去保护环境是每个人应做的事情●谓语：描述主语的情况，由动词来充当，常位于主语之后。
1.系动词：be，感官动词（表状态用）保持变化动词：She is a pretty girl. 她是个漂亮的女孩2.及物或不及物动词（表动作用）：The Internet has changed our life. 网络改变了我们的生活3.表拥有：人或物时用：have has 无生命的东西：there beI have an English book. 我有一本英语书There is a book on the table. 桌上有本书There is a pen and two book on the table. 桌上有一支笔两本书There are two books and a pen on the table.4.情态动词＋动词原形：I can swim. 我会游泳●宾语：位于谓语动词后，是及物动词或介词所指向的对象。
常做宾语的有名词、代词、宾语从句、复合结构、V-ing、To do五种。
1.名词：He read a book yesterday. 他昨天读了一本书2.宾语从句作宾语：I think (that) your spoken English is very good. 我认为你的英语口语很好3.复合结构：The advanced medical technology has made it possible for people to live longerthan ever possible before.4.V-ing: All students stopped talking when their teacher came in. 当老师进来时所有学生都停止了交谈stop doing 停下来正在做的事stop to do 停下来做另外一件事5.To do: Some people want to work for a big company while others choose to work for asmall one. 有些人想到大公司工作，然而有些人也喜欢到小公司●定语：用来修饰名词，定语主要是形容词或类似形容词的短语（例如：名词、代词、数词、介词短语、动词不定式（短语）、分词、定语从句）。
Eg: John has two red coats. 约翰有两件红色的外套The girl who wears a red coat is my sister. 定语从句= The girl in red is my sister.红衣服的女孩是我妹妹●状语：修饰副词，动词，形容词，通常是副词或类似副词的短语。
用来说明时间，地点，原因，结果，目的，条件，程度，方向，方式，伴随等。
1.时间：I usually get up at 6 in the morning. 我通常早上6点起床2.地点：He works in the hospital. 他在医院工作He is in hospital. 他现在在住院3.原因：I didn’t go to school yesterday because of ill./because I was ill. 我昨天没去学校因为我病了because of +n. because+一句话4.目的：You must speak loudly so that you can be heard by all. 你必须大声点说话目的是你的声音能被在座的每个人听见so that目的是so…that…太。
以至于。
I was so tired yesterday that I slept quickly.5.条件：If you work hard, you will pass the exam. 如果你努力学习你将会通过这次考试6.程度：He studies very hard. 他学习非常努力very 和hard 都是副词①努力学习hard修饰“studies”是副词修饰动词②非常努力very修饰hard是副词修饰副词It is so easy. 如此简单so是副词，表示非常；easy是形容词，so easy是副词修饰形容词，表示“很简单”。
副词可以修饰动词形容词副词●补语：是宾语补足语，是补充说明宾语的1. v-ing作补语：He kept me waiting the whole morning. 他让我等了一早上2. 过去分词作补语：The window was found broken. 窗户被发现已经破了3. 不定式to do作补语：He didn't allow us to smoke in his house. 他不让我们在他家里抽烟其他情况作补语allow sb. to do sth.允许某人做某事4. 其他：名词、形容词、介词短语等均可作补语用来表示状态。
名词：Lily sent me a pen. 丽丽送了我一支钢笔形容词：He always makes me laughing /laugh when I am sad. 他总是能在我悲伤的时候让我笑Make sb. do sth.使某人做某事make sb+adj.让某人保持。
状态介词短语：When he came to himself, he found himself in a hospital. 他醒来时,发现自己躺在医院里●表语：表语是用来说明主语的身份、性质、品性、特征、状态等。
表语常由名词、代词、数词、过去分词、v-ing、副词、介词短语、形容词、不定式to do、从句等来充当。
表语常位于系动词后（be，感官动词，持续变化动词），构成主系表结构1.名词充当表语: Mr. Smith is my headmaster. 史密斯先生是我的校长2.代词：-Who is that? -It is me. 谁啊？是我。
3.过去分词：The door remained closed. 门一直关着的4.v-ing：Mary’s daily job is cleaning the house.5.形容词The house is big. 房子很大6.副词：You were out when I visited you yesterday. 我昨天找你去的时候你外出了7.介词短语：He is not at home now. 他现在没在家8.不定式to do：My job is to teach you English. 我的工作是教你们英语9.从句：The reason why he came late is that his clock was broken. 他迟到的原因是他的表坏了以下动词后的动作常用doing形式1.承认admit：I admit breaking the window. 我承认是我打破了玻璃2.避免avoid：They all avoided mentioning that name. 他们都可以避免提到那个名字3.忍受stand：I cannot stand being spied. 我不能忍受被人暗中监视4.考虑consider：We're considering moving to Shanghai. 我们正考虑在搬往上海5.喜欢like=enjoy: I enjoy reading.6.完成，结束finish: I have finished doing my homework.7.练习practice: If you practice listening to the English radio, your English will improve a lot.如果你坚持听英语广播，你的英语会有很大提高8.保持keep：He has kept waiting for me for 1 hour already. 他已经等了我一小时了Sheremained standing there for an hour.9.介意mind: Would you mind opening the window? 你介意把窗户打开吗10.期待look forward to: I look forward to hearing from you. 我期待着收到你的来信同位语：是句子成分的一种，位于名词、代词后面, 说明它们的性质和情况，可以由名词、代词、名词性短或从句充当1. 名词Tom, our monitor, is a handsome boy.2. 代词I myself will do the experiment.3. 数词She is the oldest among them six.4. 从句He told me the news that the plane had exploded. 他告诉我飞机爆炸的消息5. 由such as例如, that is即引导：Some subjects, such as maths and physics, are very difficult for me to learn. 某些学科,例如数学和物理,对我来说是很难学的6. 由of引导：The city of Beijing has been greatly changed since 2000. 自从2000年以来，北京这个城市发生了很大变化7. 由or引导：The freezing temperature, or freezing point, is the temperature at which water freezes under ordinary pressure. 结冰温度即冰点, 结冰温度即冰点,是水在常压下结冰时的温度注意：fact, news, idea, truth, hope, problem, information, belief, thought, doubt, promise, question 等名词的后面,对前面的名词作进一步的解释，说明前面名词的具体含义。