專門替中國人寫的英語語法9-3：不定詞（Infinitives）

　　9-3 不定詞(Infinitives)

　　不定詞=to+動詞的原式。例如to go, to love, to eat等等，都是不定詞，不定詞和動名詞的用法相似，以下全是用不定詞用作名詞的例子：

　　To love is to forgive.

　　To forgive your enemies will make you happy.

　　I like to eat chicken.

　　I asked my brother to come here.

　　He continued to read.

　　也許讀者發(fā)現(xiàn)了不定詞和動名詞不同的地方：不定詞不能用在介系詞的后面，以下的句子都是錯的：

　　*I am interested in to play piano.

　　*He is worried about to go abroad.

　　*I am in charge of to prepare for the party.

　　如何將不定詞用成名詞呢?

　　1.不定詞可以用作主詞：如

　　To play tennis is great fun.

　　To play safe in the stock market is necessary.

　　To be kind to others is important for every one.

　　To respect your parents shows good character.

　　2.不家詞可以用成很多動詞的受詞：

　　I like to swim.

　　He loves to listen to jokes.

　　My brother seems to be different.

　　I agree to lend him money.

　　Do you like to sing?

　　3.不定詞可以跟在代名詞的后面，形式如下：

　　動詞(verb)+代名詞(pronoun)+不定詞(infinitive)

　　例如：

　　I told him to work hard.

　　I asked my brother to come back home.

　　He expects his friends to help him.

　　My teacher told me to wait for him.

　　I invited my sister to go to see a movie.

　　4.不定詞常用在上述句子的被動語氣中，例如：

　　He was told to work hard.

　　My brother was asked to come back home.

　　His friend is expected to help me.

　　I was told by my teacher to wait.

　　My sister was invited to go to see a movie.

　　以下是更多的不定詞例子：

　　To give is more meaningful than to receive.

　　I love to swim in cold weather.

　　He agreed to listen to my story.

　　He decided to go anyway.

　　I told him to buy my book.

　　I invited him to come to my house.

　　I asked him to cook for me tonight.

　　Students are asked to work hard.

　　He needs to work hard.

　　I want you to send this letter to my father.

　　He requires every student to read one novel every week.

　　Every student is required to read one novel every week.

　　讀者一定會問，是不是動名詞可以和不定詞互調(diào)，答案是否定的，有些動詞后面可以跟動名詞和不定詞，但也有些動詞，后面只能跟動名詞，有些動詞后面只能跟不定詞。

　　有些動詞后面可以跟動名詞或不定詞：love, like, hate, start, begin,以下的動詞，后面只能跟動名詞：

　　Enjoy I enjoy eating good food.

　　Appreciate I appreciate your being kind to others.

　　Avoid You should avoid making mistakes.

　　keep on Keep on working hard.

　　keep Keep singing.

　　consider He considered leaving home.

　　finish He finished writing this book.

　　suggest May I suggest drinking a cup of coffee?

　　discuss We discussed traveling to New Zealand.

　　以下的動詞正好相反，只能跟不定詞

　　agree I agree to sign this letter.

　　plan He plans to go away.

　　want They want to rent a car.

　　decide He decided to work hard.

　　seem He seems to be very happy.

　　appear He appears to be very sad.

　　一個字非常特殊，必須討論一下，那就是stop：

　　stop smoking 指不再抽煙了

　　stop to smoke 指停下來，開始抽煙