高中英语语法：四种名词性从句讲解与练习.doc

PAGE PAGE 8 名词性从句 名词性从句相当于名词，可分别作主句的主语、表语、宾语和同位语。因此，名词性从句可分为主语从句、表语从句、宾语从句和同位从句。 引导词：主语从句就是在复合句中用作主语的从句，引导主语从句的引导词主要有三类：一是that；二是whether；三是那些可以用作疑问词的词语，如what, who, which, when, where, how, why等 （一）引导名词性从句的连接词 1、连接代词：who, whose, whom, what, which。有词义，在从句中担任成分，如主语、表语、宾语、或定语等。 2、连接副词：when, where, why, how。有词义，在从句中担任成分，作状语。 3、连接词：that, whether, if, as if。that 无词义，在从句中不担任成分，有时可省略；if (whether), as if虽有词义，但在从句中不担任成分。 注意：连接代词与连接副词在句中不再是疑问句，因而从句中谓语不用疑问式。连接代词与连接副词在从句充当句子成分，连接词whether 和if（是否），as if（好象）在从句中不充当句子成分，只起连接作用。根据句义，如果连接代词与连接副词，whether、if 和as if都用不上时，才用that作连接词（that本身无任何含义）。 一、主语从句 与宾词从句连词、语序、时态相同。只是不能用if, that 不可省； （一）、主语从句是一个句子，在句子中作主语成分。 （二），主语从句的特点 1.与宾语从句使用同样的连接词，只是if 不能用； 1）、陈述句用that。 2）、一般疑问句用whether。 3）、特殊疑问句用特殊疑问词what, which, who,when, where, why, how 等词引导。 2.经常隐身（以it为形式主语出现）。 例句： 1.Its true that the earth is round. That the earth is round is true. 2. 表是否的意思时，不能用if代替whether. It hasnt been decided whether hell come or not. Whether hell come or not hasnt been decided. 3. 从句语序为主谓宾正常语序。 Why didnt he come? Why he didnt come is not known. 练习： 1.________ makes mistakes must correct them. A. What B. That C. Whoever D. Whatever 2. It worried her a bit ____ her hair was turning gray. A. while B. that C. if D. for 3.When and why he came here ________ yet. A. is not known B. are not known C. has not known D. have not known 4. ________ Tom liked to eat was different from ________. A. That…that you had expected B. What …that you had expected C. That…what you had expected D. What…what you had expected 5.________ we go swimming every day ________ us a lot of good. A. If...do B. That...do C. If...does D. That...does 6.It ________ Bob drives badly. A. thinks that B. is thought what C. thought that D. is thought that 7.Its uncertain ________ the experiment is worth doing. A. if B. that C. whether D. how 8.________ the boy didnt take medicine made his mother angry. A. That B. What C. How D. Wh