句子的成分句子成分包括：主语、谓语、表语、宾语（直接宾语、间接宾语）、补足语（主语补足语、宾语补足语）、定语和状语。
主语和谓语是句子主体部分（在英语中一般的句子必须有主语和谓语）主语：动作的执行者。
谓语：主语发出的动作。
宾语：动作涉及的对象。
表语：系动词后面的词一般就是表语。
定语：对修饰词进行限定。
补足语：对词进行补充。
状语：表示时间、地点、状态、原因、方式、结果等（如果删去，不影响句子完整）例如：We should keep the nice room clean today.主语：We谓语：should keep （是主语we发出的动作）宾语：the nice room (是谓语涉及的对象)定语：nice （修饰room）宾语补足语：clean (对nice room进行补充说明房子干净)状语：today （表示时间）主语（the subject）主语表示句子所说的是什么人或什么事。
To teach them English is my job.不定式作主语时，常用形式主语it句型，因此可变为：It is my job to teach them English.练习：找出下列句子的主语。
1、The boy comes from America.2、He usually goes to school alone.3、Studying English is very important.4、To teach him a lesson seems quite necessary.5、That he won the prize excited everyone.6、It is important for us to have our dreams.7、It is obvious that he was wrong.8、It is no use crying over spilt milk.归纳：主语一般由名词、＿＿＿＿，或者相当于名词的词、短语或从句充当(包括＿＿＿＿、＿＿＿＿还有＿＿＿＿)。
另外，当句子的主语为＿＿＿＿、＿＿＿＿或＿＿＿＿时，主语部分太长，为使句子平衡，避免头重脚轻，常用it作形式主语，把真正的主语放在后面。
谓语（the predicate）说明主语的动作、状态或特征（即主语做什么，是什么或者怎么样）。
谓语（谓语部分里主要的词）必须用动词。
一般情况下，它在主语后面。
（谓语与主语在人称与数方面要保持一致）补充：动词分为实义V、系V、情态V和助V。
实义V可单独作谓语，系V与表语一起构成谓语，说明主语的状态、性质、特征或身份。
情态V与动词原形构成合成谓语，助V与动词的适当形式（如：原形、现在分词、过去分词）共同构成谓语部分。
Eg：1) His parents are doctors.(系V表语一起作谓语)2) We have finished reading the book.（助V实义V起作谓语）3) He can speak English.（情态V实义V谓语）练习：找出下列句子的谓语并指出谓语的构成。
1、His parents are teachers.2、The sun rises in the east.3、You ought to work harder.4、I felt cold.5、He doesn’t like music.宾语（the object）宾语是动词的动作对象。
一般由n 、宾格pron（me，her等），或者相当于n的词，短语或从句充当（包括不定式、动名词还有宾语从句）。
它和及物V一起说明主语做了什么，在谓语之后。
顺序是“主语+谓语+宾语”宾语分为直接宾语和间接宾语，间接宾语说明动作是对谁或为谁而做，直接宾语则是动作的承受者或结果。
间接宾语指人，直接宾语指物。
Eg：I give him a gift.直接宾语：a gift间接宾语：him练习：找出下列句子的宾语。
1、He has never met her in person.2、She handed him a book.3、He likes to play basketball.4、We enjoy listening to music.5、She said that she felt sick.6、They sent the injured to hospital.7、I find it impossible to believe her any longer.8、We consider it no good getting up late.9、They believed it strange that he should have done that.归纳：当句子的宾语为＿＿＿、＿＿＿＿、或＿＿＿＿＿时，常用形式宾语it，以保持句子的平衡。
表语（the predicative）表语说明主语是“是什么”“怎么样”。
系V是表示人或事物状态、性质的V。
系V后面的部分叫表语。
作表语的典型词类是adj，也可以是n、数词、极少数adv（如here, there）、介词短语、不定式。
分词、表语从句等。
系V与表语共同构成谓语，说明主语的状态、性质等。
Eg：1）You look younger than before.2)I am a teacher.3)Everybody is here.4)They are at home now.5)My job is to teach them English.练习：找出下列句子的表语并指出表语是由什么来充当的。
1、My wallet is on the desk.2、The book isn’t mine.3、The leaves turn yellow in fall.4、He has become a police officer.5、My suggestion is that we should start at once.6、My suggestion is to leave at once.7、His speech was boring.8、The whole class got excited at the good news.拓展：系V（link verbs）英语中有相当多的系V，都可跟一个表语，与之构成符合谓语。
有3类：1、表示特征或状态的系V，如：be , feel , look , sound , taste , smell , seem , appear2、表示状态转变的系V，如：become , grow , get , turn , fall, go , come , run3、表示保持某种状态的系V，如：remain , continue , keep , stay , prove , turn outeg：1)She remained quite calm.她保持相当冷静。
2)The weather continued fine for several days. 好几天天气都很好。
助V助动词：be , do , have情态V：1、can / could2、may / might3、must / have to4、shall / should / ought to5、will / would6、used to7、be to8、be supposed to9、be about to 10、need 11、dare 12、had better定语（the attribute）定语用来修饰n或pron，起限定作用。
作定语的典型词是形容词和形容词性物主代词，也可以是数词、名词、介词短语、分词、定语从句等。
定语一般位于被修饰词之前，但若修饰复合不定代词（如something）时，或者是短语或定语从句作定语，则总是放在所修饰n的后面。
Eg：1）The black bike is mine. ( adj )2) What is your name? ( pron )3) They made paper flowers. ( n )4) The boys in the room are in Class Three, Grade One. ( 介词短语)5) I have something to do. （不定式）练习：找出下列句子的定语并指出定语是由什么充当（形容词、形容词性代词、数词、名词、介词短语、分词还是定语从句）1、The beautiful sight attracts many tourists every year.2、The wallet on the desk is mine.3、The demanding boss wasn’t satisfied with my work.4、That building being repaired is our library.5、He is one of the students that have been late.6、The excited boys burst into cheers.7、The woman police officer was praised for her good work.状语（the adverbial modifier）状语用来修饰V、adj 、adv或整个句子。
一般表示行为发生的时间、地点、目的、方式、程度等，作状语的典型词是adv，也可以是介词短语、不定式、分词、状语从句等。
Eg：1) He did it carefully.2) Without his help, we couldn’t work it out.3) (In order ) to catch up with my classmates, I must study hard.练习：找出下列句子的状语并指出状语是由什么充当（副词、介词短语、不定式、分词、状语从句）。
1、He did his homework carefully at home.2、Her mother goes out to do some shopping on Sunday.3、When I grow up, I am going to be a teacher.4、Feeling tired, he went to bed without supper.5、He lost his job due to his lack of patience.6、Brought out in the country, he finds it hard to adjust himself to city life.补足语（the complement）补充说明主语的称为主语补足语；补充说明宾语的称为宾语补足语。