罗玉南
名词性从句是中学英语语法的重点和难点，现把在使用名词性从句过程中应注意的几个方面总结以下，供同学们学习参考。
一忌 that与what混淆
what引导的名词性从句意为“……的东西（事情）”或“什么”，相当于all that。如：
【误】That he needs to get rid of smoking is your help．
【正】What he needs to get rid of smoking is your help．
【正】All (that) he needs to get rid of smoking is your help.that引导定语从句。
二忌 多that
引导名词性从句的连接代词who, whose, which, what, 连接副词how, why, where, when和连词if，whether等前，不可再用that。如：
【误】I wonder that when they got to know each other．
【正】I wonder when they got to know each other．
三忌 少that
引导名词性从句的that在句中无具体意思，但在下列情况下，that不可省略：
1．宾语从句被分隔或提前时；
2．宾语从句不止一个时；
3．引导主语从句、表语从句或同位语从句时。如：
【误】We don’t doubt, in any case, he keeps his word．
【正】 We don’t doubt, in any case, that he keeps his word．
（插入语in any case将宾语从句与谓语动词分隔开，故不可省略that。）
【误】Everyone could see what was happening and poor Mary was nearly frightened．
【正】Everyone could see what was happening and that poor Mary was nearly frightened． （what was happening和that poor Mary was nearly frightened为并列的宾语从句，故不可将that 省略。）
【误】The earth goes around the sun was not widely accepted at that time．
【正】That the earth goes around the sun was not widely accepted at that time． （that 引导主语从句时不可省略。）
【误】The problem is fuels like coal and oil cause a lot of pollution．
【正】The problem is that fuels like coal and oil cause a lot of pollution．（that 引导表语从句时不可省略。）
【误】We heard the news our team had won．
【正】We heard the news that our team had won．
that引导同位语从句时不可省略。
四忌 that, why和because三者混淆
有些名词如reason，cause等作句子的主语时，其后的表语从句常用that引导，不可误用because；because引导表语从句时常用于That’s because…这一句型，说明产生上述结果的原因；why引导名词性从句说明由上述原因而导致的必然结果。如：
【误】The reason why he hasn’t come is because he has not received the invitation．
【正】The reason why he hasn’t come is that he has not received the invitation．
【误】I was very late for school this morning． That’s why I stayed up too late last night．
【正】I was very late for school this morning． That’s because I stayed up too late last night．（前面为结果，后面为原因。）
【正】I stayed up too late last night． That’s why I was very late for school this morning．（前面为原因，后面为结果。）
五忌 if, whether 和that三者混淆
if多在口语中引导宾语从句；在正式语体中或当引导主语从句、表语从句、同位语从句时则用whether；在doubt等后的宾语从句中熆隙ň涑８鷚hether或if引导的从句，否定句或疑问句则常跟that引导的从句。如：
【误】If they will hold a sports meeting is not decided．
【正】Whether they will hold a sports meeting is not decided．
【误】I doubt that that was what he wanted．
【正】I doubt if that was what he wanted．
六忌 语序倒装
名词性从句一律用陈述语序。如：
【误】When will the meeting start is unknown to all．
【正】When the meeting will start is unknown to all．
七忌 从句时态错误
主句谓语动词的时态为过去时态，名词性从句谓语动词的时态一般要受其影响，要用相应的过去时态（表示客观真理时用一般现在时）。如：
【误】The man asked his wife where they’ll spend the night．
【正】The man asked his wife where they would spend the night．
【误】We don’t know when he returns in the future．（误为时间或条件状语从句）
【正】We don’t know when he will return in the future。
八忌 从句语气错误
名词性从句经常出现在用来表示一个并非基于事实的假设的虚拟语气中。
一、.虚拟语气中的主语从句。常见的句型有：
1．It is／was＋形容词＋that＋主语（从句）＋（should）＋动词原形……
常用在该句型中的形容词有： important，impossible，normal，natural，necessary， sorry，strange，等，如：
【误】It was necessary that the plan was planned carefully．
【正】It was necessary that the plan（should） be planned carefully．
2.表示“请求、命令、建议、决心”等意义的名词。如：advice，demand，decision，，order，proposal，requirement， request，suggestion 等，如：
【误】It is my suggestion that we will get everything ready tonight．
【正】It is my suggestion that we（should） get everything ready tonight．
3．It is ／was ＋动词过去分词＋ that＋主语（从句）＋（should）＋动词原形……
用在该句型中的动词过去分词表示“请求、命令、建议”等意义。如：advised， begged，desired， demanded，insisted， ordered，proposed，requested， required，suggested 等，如：
【误】It was suggested that each student must sing a song．
【正】It was suggested that each student（should）sing a song．
二、虚拟语气中的表语从句与同位语从句。某些表示“建议、请求、命令”等意义的名词后的表语从句或同位语从句需用“（should）＋动词原形”构成谓语。这类名词有：advice，desire，decision， idea，order，plan，proposal， request，suggestion等，如：
【误】We agree to his idea that we will put on a short play at the party．
【正】We agree to his idea that we（should）put on a short play at the party．
【误】His suggestion was that we would go there by train．
【正】His suggestion was that we（should）go there by train．
另外，as if／as though 引导的表语从句，谓语动词用：过去时表示与现在事实相反；过去完成时表示与过去事实相反。如： You look as if／though you were ill．
三、虚拟语气中的宾语从句。
1.某些表示“愿望、请求、建议、命令、决心”等意义的动词后的宾语从句需用“（should）＋动词原形”构成谓语。这类动词有：advise，ask，demand，insist，order，propose，request，require，recommend，suggest， urge等，如：
【误】The teacher suggested that we had a meeting．
【正】The teacher suggested that we（should）have a meeting．
2.动词 wish 后的宾语从句，若表示不能实现的愿望，谓语动词用过去时表示与现在事实相反的愿望；用过去完成时表示与过去事实相反的愿望；用“would ／could ／might＋动词原形”表示与将来可能发生的事情相反的愿望。如：
【误】How I wish I saw you yesterday!
【正】How I wish I had seen you yesterday!