动词不定式和动名词放句首有什么区别

动词不定式和动名词(ing)作主语比较 一。动词不定式表示比较具体的意义,经常和特定的动作和执行者联系起来,经常带时间或地点状语,有时表示将要发生的动作。To master a foreign language is no easy job。To do it well is my earnest desire To see this film is to waste time。To solve this problem is out of the question 动词不定式（短语）作主语时,常见的另一种形式是在句首用先行代词it作形式主语,而将动词不定式（短语）移到谓语之后作真正主语。用于这种形式是一些特定形容词,动词和名词 1)形容词作表语（常见的形容词有：important,difficult,easy hard possible） It is foolish to act in this way。It sounds reasonable to do it this way。It appears likely for them to arrive。2) 动词作谓语（常见的动词有：require,cost,amuse,delight,irritate,annoy) It took much time to do this。It makes us excited to think about that。It needed hard work to finish the job。It does no good to say like that。It didn't occur to me to ask him to help me。3)名词作表语 It seems a pity to waste them。It is a great pleasure to do this It is a good idea to think this way。二。动名词表求比较抽象（一般）和经常性的意义,有时可同不定式互换 Collecting stamps is a good hobby。Swimming is a best sport in summer。There is no telling what will happen。There is no denying the fact。There is no need informing him of it。动名词短语作主语时,常见的另一种形式是在句首用先行代词it作形式主语面将动名词短语移至谓语之后作真实主语。用于这种形式是一些特定形容词和名词 1)形容词作表语(常见的形容词有：enjoyable,good,hard,worthwhile) It is nice talking to you。It's foolish behaving like that。It is useless doing that 2)名词作表语 It's waste of time doing this。It's no good (use) doing that。It's an awful job doing this。It's fun doing thisIt is not an easy task doing this work。