簡介
1.不定式定義:
不定式是一種非限定性動詞。而非限定動詞是指那些在句中不能單獨充當謂語的動詞,可分為不定式,動名詞,現在分詞和過去分詞。
2.用途:
在句中不能作謂語。它具有動詞的性質,本身可以帶賓語和狀語。
3.形式:
動詞+不定式:由to+動詞原形構成。
動詞不定式在句中可以作句子任何成分。動詞不定式的被動形式除了一般形式外還有其完成式和進行式。
作定語
⒈不定式作定語
不定式在句中作定語,置于被修飾的名詞或代詞之後。如:
①The next train to arrive is from Washington.
②Do you have anything to be taken to your sister?
③Do you have anything to say on the question?
④Would you please give me some paper to write on?
⑤My wish to visit France has come true at last.
不定式短語作定語和被修飾詞之間表示以下關系:
(1)表示将來的動作(例①)。
(2)與被修飾詞之間有動賓關系,如是不及物動詞,則需加介詞(例④)。
(3)與被修飾詞之間有動賓關系,同時與句中其它詞之間又有邏輯上的主謂關系時,盡管有被動含義,卻仍用主動語态(例③);如隻有動賓關系,而無邏輯上的主謂關系,則需用被動語态(例②)。
(4)不定式作定語時,一般可轉換為定語從句,例①to arrive=that will arrive。
進行式
形式
to be +現在分詞
He seems to be following us.
他好像在跟着我們。
用法
①用于助動詞之後
He must be coming by bus.
他一定是乘公共汽車來的。
You shouldn't be reading a novel.
現在你不應該看小說,你應該看課本。
②用于apprar,happen,pretend,seem之後
I happened to be standing next to him when he collapsed.相當于:
It happened that I was standing next to him when he collapsed.
他倒下的時候我恰巧站在他身邊。
③hope和promise之後,或agree,arrange,decide,determine/be determined,plan,undertake之後,但用于hope和promise後更常見:
I hope/hoped to be earning my living in a year's time.相當于:
I hope I will/I hoped I would be earning……
我希望在一年之内能自食其力。
完成進行式
形式
to have been +現在分詞
He seems to have been spying for both sides.
他似乎一直在為兩方面搞秘密情報。
用法
隻要用于助動詞之後和appear,seem之後,但也可以用在happen,pretend以及believe,know,report,say,understand的被動式之後:
He appears to have been waiting a long time.相當于:
It appears that he has been waiting a long time.
看來他已經等了很久了。
He pretended to have been studying.相當于:
He pretended that he had been studying.
他假裝一直在學習的樣子。
句型用法
在There be句型中的動詞不定式:
For example one,There are too much homework to write.
two,There are students writing too much homework.