名词性从句应注意的问题种种

作者:聂艳红

　　 名词性从句是学生学习中的重点和难点，这里简要介绍一下应注意的有关问题。
　　
　　 一、 六忌
　　
　　 (一) 注意不可多that
　　 连接代词who, whom, which, whose, what;连接副词how, why, when, where; 连接词if, whether; 所有这些词前，不可再用that。例如：
　　 He doesn’t know that when they arrived here.(去掉that)
　　 (二) 注意不可少that
　　 引导名词性从句的that在句子中无具体意思，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。例如下列句子中不可省略that：
　　 I don’t doubt, in any case, he keeps his word.(应在he前加上that)
　　 Everyone could see what was happening and poor Tom was nearly frightened. (应在and后加上that)
　　 The earth goes round the sun was not widely accepted at that time.(应在句首加上That)
　　 The problem is fuels like coal and oil cause a lot of pollution.(应在is 后加上that)
　　 We heard the news our team had won.(应在news后加上that)
　　 (三) 注意that与what的用法
　　 that没有意义，在句中只起引导的作用，不作成分；what意为“……的东西（事物）”，在从句中可作主语或宾语、表语、宾语补足语。例如：
　　 That he needs is your help.(把That改成What)
　　 1) ________we can’t get seems better than_ _______we have.
　　 A. What; what B. What; that
　　 C. That; that D. That; what
　　 2) ________ fashion differs from country to country may reflect certain cultural differences.
　　 A. What B. That C. This D. Which
　　 3) People were perhaps more honest a long time ago when life was very different from ________it is today.
　　 A. which B. that
　　 C. what D. how
　　 4) The word media basically refers to ________we commonly call newspapers, magazines, radios and televisions.
　　 A. which B. what C. why D. that
　　 (四) 注意区分that, because和why
　　 有些名词如reason, cause作句子的主语时，其后的表语从句常用 that引导，不可用because; because引导表语从句时用于句型That’s because ... ,说明产生上述结果的原因；why引导从句时说明由上述原因导致的必然结果。例如：
　　 The reason why he hasn’t come is because he hasn’t received the invitation.(把because 改成that)
　　 I was very late for school this morning. That’s why I stayed up too late last night.(把why改成because)
　　 (五) 注意区分that, if, whether
　　 1. 在doubt后面的宾语从句中,肯定句常跟whether或if引导的从句；否定句常跟that引导的从句。例如：
　　 I doubt that that was what he wanted. (应把第一个that改成if或whether)
　　 2. if和whether
　　 用whether而不用if的情况：
　　 1) 引导主语从句、表语从句和同位语从句时；
　　 2) 在介词后引导宾语从句时；
　　 3） 后面直接跟动词不定式时；
　　 4） 后面紧跟or not时例如：
　　1) ________we’ll go camping tomorrow depends on the weather.
　　 A. If B. Whether C. That D. Where
　　2) It all depends on ________they will support us.
　　 A. whether B. what C. if D. that
　　3) He doesn’t know ________ to stay or not.
　　A. whether B. if
　　C. either D. if he will
　　4) We didn’t know___ _D _____or not she was ready.
　　We didn’t know___ A / D ___she was ready or not.
　　A. if B. what C. that D. whether
　　(六) 注意语序（一律用陈述语序） 例如：
　　 When will the meeting start is unknown to all.(把will the meeting 改成the meeting will)
　　
　　 二、 四种特殊的宾语从句
　　
　　 (一) 在下列动词后跟宾语从句时，从句的谓语动词常使用虚拟语气，即(should) + do。这里我们把它总结为“一个坚持、命令；两个建议；三个要求”，即insist（坚持，坚决要求），order, suggest(建议), advise, require, demand, request。例如：
　　 I suggest that we should start at once.
　　 He insisted that he be sent to the front line.
　　 The workers demanded that the boss should give a rise as soon as possible.
　　 (二) wish后面的宾语从句往往表示“难以实现或不能实现的愿望”，谓语动词也体现为虚拟语气。
　　 1. 从句表示与现在事实相反时，从句用一般过去时（did / were）；
　　 2. 从句表示与过去事实相反时，从句用过去完成时（had done）；
　　 3. 从句表示将来不能实现的愿望时，多用could / would + do。例如：
　　 I wish I were a bird.
　　 He wished he had finished his homework yesterday.
　　 I wish I could fly to the moon one day.
　　 (三) 当主句的主语为第一人称，动词为think, believe, suppose, imagine，宾语从句的谓语为否定形式时，否定应转移到主句中。例如：
　　 I don’t think you are right.
　　 We didn’t believe that this was true.
　　 (四) 为了避免句子成分不清楚，结构不平衡，在think, consider, make, feel等词后面，常用it作形式宾语，而将真正的宾语从句放在后面。例如：
　　 I think it useful that we can learn English well.
　　 Mary feels it her duty that she helps whoever needs help.
　　 The headmaster made it clear that he didn’t cheat the students in fact.