不定式與動名詞作主語的比較

1、動名詞和不定式作主語的比較 在中學(xué)英語課本中，動名詞和不定式作主語的句子較為常見，但它們的含義有所不同?，F(xiàn)在將動名詞和不定型式作主語的含義、位置及習(xí)慣用法分述如下：一、動名詞和不定式作主語的含義一般來說，動名詞作主語表示一種抽象的和泛指的動作，而不定式作主語則表示一次性的、具體的動作。換句話說，動名詞作主語通常不與特定的動作執(zhí)行者聯(lián)系在一起，而不定式作主語往往與特定的動作執(zhí)行者聯(lián)系在一起。例如：Lying is wrong.（泛指lying的做法或作風(fēng)）To lie is wrong.（對于說謊者是誰，說話人心中是有所指的）To live in Beijing is the height of

2、 Toms ambition.（對某個特定的動作執(zhí)行者而言）Swimming is good exercise.（指游泳這項運動）二、動名詞和不定式作主語的位置1動名詞作主語通常有兩種位置，一種是把動名詞直接置于主語的位置。例如：Saying is easier than doing.Seeing is believing.Crossing the Atlantis（大西洋）by plane takes only a few hours.第二種是用it作形式主語，把作真正主語的動名詞置于句末。這通常用于某些形容詞或名詞之后。例如：Its interesting planning a holid

3、ay.Its rather tiring walking around in a city.Its fun having guests for the weekend.We dont think its a bore doing the same kind of work every day.動名詞作主語的上述兩種位置有時可以互換，但第一種形式比第二種形式的泛指意義更強些。例如：Lining in Beijing must be wonderfulIt must be wonderful living in Beijing2不定式作主語通常也有兩種位置，與動名詞作主語時的位置相同，即第一種是把

4、不定式作直接置于句首擔(dān)任主語。例如：To learn English is not an easy thing.To be here is a great pleasure.To remember to cut off the electricity is important.To hesitate is a pity.不定式作主語的這種形式一般用得不多。現(xiàn)代英語傾向于用it作形式主語，把不定式置于句末。例如：Its a pity to hesitate.It took（us ）five hours to get here.It made me happy to find Mary there

5、.It needed hard work to finish the job.注意：（1）如果主語和表語都是不定式，則只能采用第一種形式。例如：To be kind to the enemy is to be cruel to the people.To see is to believe.（2）如果是疑問句或感嘆句，則只能采用第二種形式。例如：What is it like to be there？How long did it take you to finish the work？What a joy it was to read Barbaras book！三、動名詞和不定式作主語的習(xí)

6、慣用法雖然動名詞和不定式都可以作主語，但以下幾種情況時，人們習(xí)慣用動名詞，而不用不定式。1主語與表語一致，即當(dāng)表語是動名詞時，主語也要用動名詞；當(dāng)表語是不定式時，主語也要用不定式。Teaching is learning.（= To teach is to learn）Seeing is believing2在“There BE+no+主語”這種結(jié)構(gòu)中，通常用動名詞作主語，而不用不定式。這種結(jié)構(gòu)表示“不可能、無法”，相當(dāng)于“It is impossible to do sth”。例如：There is no getting along with him.（=It is impossible t

7、o get along with him.）There is no joking about it.注意：本句型中的no有時可用not any或never any代替。例如：The man is a bore，but there is not any getting him away.There is never any telling what will happen in the future.3當(dāng)use，good，waste，bore，fun，shame，encouragement，misery等名詞作表語時，通常用it作形式主語，把作為真正主語的動名詞后置。例如：Its no use

8、talking to him again.Its no good（your）refusing to do it.It is a waste of time trying to reason with him.Its a bore doing the same kind of work every day.Its fun having guests for the weekend.Its such an encouragement being able to pass all the exams.注意：“Its no use /good+動名詞”這種結(jié)構(gòu)可改成“There BE+no+use /

9、good+動名詞”結(jié)構(gòu)。例如：Its no use talking to him again .= There is no use talking to him again.Its no good（your）refusing to do it .= There is no good（your）refusing to do it.4當(dāng)，interesting，tiring，terrible，nice，better，foolish，enjoyable，worthwhile，useless，dangerous等形容詞作表語時，通常也用it作形式主語，把作為真正主語的動名詞后置，例如：It is dangerous risking climbing a tree.Its terrible not being allowed to smoke at all.Its interesting planning a holiday.Its nice talking with you，John.注意：important，necessary，possible，impossible，essential等形容詞不適用于上述結(jié)構(gòu)。例如，不能說：Its important learning forei