1、名词性从句讲解I语序问题规律一：名词性从句在句中要用陈述语序 II引导词的选择1.从句是陈述句转化而来的，不含有疑问意义。由that 引导且that连词在从句中不作成分2.从句是由一般疑问句转化而来，含有疑问意义的。由whether，if 引导3.从句是由特殊疑问句转化而来，含有疑问意义的。由wh-连词引导且 wh-连词在从句中作成分。连接代词what / who/ which / whose / whatever / whoever / whomever / whichever，连接副词where / when / why / how / wherever / whenever。 规律二：
2、whether和if的区别whether和if在宾语从句中可以互换，但是作介词宾语时连接词一般用whether。如：It all depends on whether they will come back.后面直接跟or not 时用 whether。如：I didnt know whether or not he had arrived in Wuhan主语从句和表语从句中只能用whether。如：Whether the meeting will be put off has not been decided yet.The question is whether they have so
3、 much money.whether可以引导同位语从句，用以说明前面的名词的内容，if不能。如：We ought to discuss carefully the question whether we can do it or not.whether常与or连用表示一种选择，if不能这样用；whether也可与动词不定式连用但if不能。如：The question of whether they are male or female is not important.I have not decided whether to go or not. whether可引导一个让步状语从句表示“
4、不管”、“无论”，而if不能，但可以引导一个条件状语从句表示“如果”如：Whether he comes or not, we will begin our party on time.If I have time tomorrow, Ill go to visit Tom 规律三：主语从句和宾语从句在适当的情况下可以借助 “it” 而后置。1.主语从句可以用it （作形式主语） 来替换成以下几种结构表达。(A)It is clear/certain/likely /true/surprising that （B）It is a pity/shame/good idea/no wonder t
5、hat .（C）It is said/reported/ believed/known/thought/suggested that （D）It seems/happens that2.宾语从句可以用it（作形式宾语） 来替换的句型为：主语谓语itAdj/N从句如： I think it necessary that we have the meeting 规律四：whatever, whichever, whoever, whenever, wherever, however 等与 no matter what, no matter which, no matter who, no matt
6、er when, no matter where, no matter how 的区别:前者既可以引导名词性从句，也可以引导让步状语从句，而 no matter 加疑问词只能引导让步状语从句。 规律五：注意虚拟语气在名词性从句中的运用(1)虚拟语气在宾语从句中的运用。“wish + 宾语从句”表示不能实现的愿望，译为“要是就好了”等。表示现在不能实现的愿望，从句中的谓语动词用一般过去时；表示将来不能实现的愿望，从句中的谓语动词用“would/could + 动词原形”；表示过去不能实现的愿望，从句中的谓语动词用“had + 过去分词”在表示建议、要求、命令等的动词suggest、advise、
7、propose、demand、require、insist request、command、order等动词后的宾语从句中，从句谓语动词用(should) + 动词原形或是动词原形。如：She suggested we (should)leave here at once.The doctor ordered she (should )be operated on.（2）虚拟语气在同位语从句和表语从句中的运用。作表示建议、要求、命令等的名词advise、idea、order、demand、plan、proposal、suggestion、request等的表语从句和同位语从句，从句中的谓语动词
8、用“（should） + 动词原形”。如：His suggestion that we (should)go to Shanghai is wonderful.My idea is that they (should)pay 100 dollars.（3）虚拟语气在主语从句中的运用。在主语从句中，谓语动词的虚拟语气用“should + 动词原形”的结构，表示惊奇、不相信、理应如此等。如：It is necessary(important, natural, strange, etc.)that we should clean the room every day.It was a pity (a shame, no wonder, etc.)that you should be so careless.