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一般所见到的句子结构中，通常是以名词作主语，但除了名词以外还可以用代词、动名词、不定式短语、名词性从句、名词短语、表距离的地点副词短语等做主语。 分别说明如下： 1、名词作主语 The child is my daughter. 2、代词做主语 He always keeps his promise. 3、动名词或不定式短语作主语 动词一定一定不能做主语，要变成动名词或者不定式短语，如此才能和名词对等。 Seeing her makes me angry. To see him is my purpose of coming here. （1）那么什么情况下用动名词做主语呢？一般情况下是用来表示已知的事实或曾经做过的经历。 例1.collecting stamps is one of my hobbies. 例2.Listening to music makes me happy. 这里collecting stamps和Listening to music都是以往的一种经历。 （2）用不定式做主语时，通常表示一种意愿、目的或尚未做的事。 To study in the United States is my greatest desire. To go to Japan for a visit is my plan for this year. 注意： 不定式或动名词作主语时往往造成主语太长的情况（如上），故通常用代词it置于句首做形式主语，而将真正的主语移至句尾。但是，动名词移至句尾时通常要改为不定式短语。 Collecting stamps is one of his hobbies. = It is of his hobbies to collect stamps. To study in the United States is my greatest desire. = It is my greatest desire to study in the United States. 例外：It is no use + 动名词短语。这里不可使用不定式短语，千万千万记住哦！ It is no use crying over split milk. 但是，当你把no use 换成useless或者ofone use 后面可跟不定式短语。 4、名词性从句做主语 首先得弄清楚什么是名词性从句？它起什么作用？ 定义：在句子中起名词作用的句子叫名词性从句(Noun Clauses）。 我们都知道在英语中名词可以作主语、宾语、同位语、表语 、定语、状语、补语。 因此根据在句中不同的语法功能名词性从句可分为： A.主语从句（作主语）：That the earth is round is true. B.宾语从句（作宾语）：Do you know where he lives. C.表语从句（作表语）：My opinion is that you should not go alone. D.同位语从句(于解释说明前面的名词)： The fact that the earth is round is true. 根据构成来看名词性从句一共有三种： （1）That从句。任何一个主语起首的句子前加That就是that从句。 例.That the earth is round is true. （2）Whether 从句。 Whether从句由可用yes或no回答的一般疑问句变化而成. 具体分为： A. 问句有be动词和助动词（can、will、may、should、ought to、have、must）时。 主语与be动词或助动词还原，前面加上whether，这就形成了whether从句。 例1.Is he happy?→ whether he is happy. I don’t know whether he is happy. Whether从句在复合句中作宾语 例2.can he do it? →whether he can do it. Whether he can do it is still unknown. Whether从句在复合句中作主语。 B. 问句有do、does、did等助动词时。 主语与助动词还原，再将助动词Do、does、did去掉，后面的动词依人称和时态变化。 例1. Did he come? →whether he did come → whether he came. 例2. Does he like it? →whether he likes it （3）疑问词所引导的从句。 由疑问词（when、what、how、where、why）等特殊疑问句变化而成。具体分为： A. 问句有be动词和助动词时。主语与be动词或者助动词还原，前面保留疑问词。 例1. What are you doing? → what you are doing I want to know what you are doing.在复合句中作宾语 例2. Where can he find it? → wherehe can find it. Where he can find it is unknown. 在复合句中作主语 B. 问句有do、does、did等助动词时。主语与助动词还原，前面保留疑问词；再将助动词Do、does、did去掉，后面的动词依人称和时态变化。 例1. what did he write? → what he wrote. 注意：Who、what、which为疑问代词，若在句中作主语，变成名词性从句时结构不变。 例1. who came here. 例2. What happened last night. 例3. Which was bought. 5、名词短语作主语 名词短语由“疑问词 ＋ 不定式短语”形成 ① 疑问副词 Where to live Whether to try again When to talk to him How to do it 例1. Where to live is still unknown. 例2. Whether to try again is still not decided ② 疑问代词 What to do Whom to see Which to by 例.which to buy depends on how much money do you have. 6、表距离的地点副词短语做主语 From + 地点 + to + 地点 例.From shanghai to Beijing is about 1000 kilometers. 如果主语太长可以用it代替做形式主语。 |
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