主語從句
1）主語從句可直接位於主語的位置，如果從句較長，謂語又較短，可用it作形式主語，而將從句放在句末。常見的句型有：
*It is a fact\a pity\a question\good news that...
*It seems\appears\happened\has turned out that...
*It is clear\important\likely\possible that...
*It is said\reported\estimated\has been proved that...
It is said that comic books create a connection between people of the same generation.
It seems that the performance is very useful.
2)what引導的主語從句表示“...的東西時”，一般不用it作形式主語。
What we lack is experience.
3)what,who,when,why,whether等詞含有各自的疑問意義，但它們引導的主語從句，都用陳述語序。
How the plan is to be carried out should be discussed again.
I did know why I felt like crying.
2.賓語從句
1）賓語從句可位於及物動詞、介詞和某些形容詞後。連詞that常可省略。介詞後一般接疑問詞引導的賓語從句。in that(因為),except that(除了),but that(只是）已構成固定搭配，其他介詞後一般不接that引導的賓語從句。
*I promised that I would change the situation.
*All this is different from what American young people would say about friendship.
*He is certain that watching so much television is not good for children.
*This article is well-written except that it is a bit too long.
2)賓語從句後如有賓補，要用形式賓語it來代替，而把賓語從句移至賓補之後。
He has made it clear that he would not change his mind.
3)在think,believe,suppose,expect等動詞後的賓語從句中，如果謂語是否定的，一般將否定詞移至主句謂語上，賓語從句則變成肯定形式。
He didn"t think that the money was well spent.
3.表語從句
表語從句出現在結構為“主語+系動詞+表語從句”的句子中。表語從句除可用that,what,when,why,whether,how等引導外，還可由because,as if(though)等引導。that常可省略。如主句主語為reason,只能用that引導表語從句，不可用because.
Perhaps the most important thing to remember is that there is no one common type of life in America.
The reason why so many people died there is that there were not enough food supplies.
It looks as if successful international cultural communication will make the world smaller.
4.同位語從句
同位語從句用於對前面出現的名詞作進一步說明，一般用連詞that引導，由於先行名詞的意義不同，也可用whether,who,when,where,what,why,how等引導。常見的先行名詞fact,idea,belief,news,hope,conclusion,evidence,suggestion,order,problem,report,decision.有時由於謂語較短，將同位語從句位於謂語之後。
She finally made the decision that she would join the fashion show.
I had no idea how many books I could borrow at a time.
The news came that their team had won the championship.
5.定語從句
定語從句所修飾的先行詞可以是名詞或代詞，也可以是一個句子。定語從句通常位於先行詞之後，由關係代詞或關係副詞引導。
*限制性定語從句
限制性定語從句修飾先行詞，對先行詞起修飾作用，緊接先行詞之後，無逗號，若省去，原句意思不完整。引導定語從句的關係代詞有who,whom,whose,which,that等。who,whom,whose用於指人，whose有時也可指物，相當於of which；which用於指物；that既可指人也可指物，但只用於限制性定語從句中。關係代詞除了引導定語從句，替代先行詞外，還在從句中擔任主語、賓語、定語等。
The computers and cables which make up the Internet are owned by people and organizations.
Those who live alone or who are sick may have trouble in getting close to other people.
The girl whose parents died in an accident is living with her grandmother.
主語從句
1）主語從句可直接位於主語的位置，如果從句較長，謂語又較短，可用it作形式主語，而將從句放在句末。常見的句型有：
*It is a fact\a pity\a question\good news that...
*It seems\appears\happened\has turned out that...
*It is clear\important\likely\possible that...
*It is said\reported\estimated\has been proved that...
It is said that comic books create a connection between people of the same generation.
It seems that the performance is very useful.
2)what引導的主語從句表示“...的東西時”，一般不用it作形式主語。
What we lack is experience.
3)what,who,when,why,whether等詞含有各自的疑問意義，但它們引導的主語從句，都用陳述語序。
How the plan is to be carried out should be discussed again.
I did know why I felt like crying.
2.賓語從句
1）賓語從句可位於及物動詞、介詞和某些形容詞後。連詞that常可省略。介詞後一般接疑問詞引導的賓語從句。in that(因為),except that(除了),but that(只是）已構成固定搭配，其他介詞後一般不接that引導的賓語從句。
*I promised that I would change the situation.
*All this is different from what American young people would say about friendship.
*He is certain that watching so much television is not good for children.
*This article is well-written except that it is a bit too long.
2)賓語從句後如有賓補，要用形式賓語it來代替，而把賓語從句移至賓補之後。
He has made it clear that he would not change his mind.
3)在think,believe,suppose,expect等動詞後的賓語從句中，如果謂語是否定的，一般將否定詞移至主句謂語上，賓語從句則變成肯定形式。
He didn"t think that the money was well spent.
3.表語從句
表語從句出現在結構為“主語+系動詞+表語從句”的句子中。表語從句除可用that,what,when,why,whether,how等引導外，還可由because,as if(though)等引導。that常可省略。如主句主語為reason,只能用that引導表語從句，不可用because.
Perhaps the most important thing to remember is that there is no one common type of life in America.
The reason why so many people died there is that there were not enough food supplies.
It looks as if successful international cultural communication will make the world smaller.
4.同位語從句
同位語從句用於對前面出現的名詞作進一步說明，一般用連詞that引導，由於先行名詞的意義不同，也可用whether,who,when,where,what,why,how等引導。常見的先行名詞fact,idea,belief,news,hope,conclusion,evidence,suggestion,order,problem,report,decision.有時由於謂語較短，將同位語從句位於謂語之後。
She finally made the decision that she would join the fashion show.
I had no idea how many books I could borrow at a time.
The news came that their team had won the championship.
5.定語從句
定語從句所修飾的先行詞可以是名詞或代詞，也可以是一個句子。定語從句通常位於先行詞之後，由關係代詞或關係副詞引導。
*限制性定語從句
限制性定語從句修飾先行詞，對先行詞起修飾作用，緊接先行詞之後，無逗號，若省去，原句意思不完整。引導定語從句的關係代詞有who,whom,whose,which,that等。who,whom,whose用於指人，whose有時也可指物，相當於of which；which用於指物；that既可指人也可指物，但只用於限制性定語從句中。關係代詞除了引導定語從句，替代先行詞外，還在從句中擔任主語、賓語、定語等。
The computers and cables which make up the Internet are owned by people and organizations.
Those who live alone or who are sick may have trouble in getting close to other people.
The girl whose parents died in an accident is living with her grandmother.