(九)為了避免重復(fù)，不定式可省略，但to有時(shí)保留，有時(shí)不保留。例如：

　　You will make it if you try (to). 如果你努力，你會成功的。

　　George says he is going to leave Shanghai, but I don’t think he really wants to. George 說要離開上海，但是我不認(rèn)為他真的愿意走。

　　Some of them retired, and others were ready to. 一些人退休了，還有的準(zhǔn)備退。

　　He always speaks faster than he needs to. 他說話總是沒必要的快。

　　I’d like to do it now, but I haven’t got the time (to).  我倒是想現(xiàn)在干，但沒時(shí)間。

　　“Would you go there with me?” “I’m glad to.” “你愿意和我一起去嗎?”“愿意。”

　　“Did you pass the exam?” “No, I tried (to), but I failed.” “你考試及格了嗎?”“沒有，我努力了，但沒成功。

　　“Do you want to sing them an English song?” “I prefer not to.” “你愿意為他們唱首英文歌嗎?”“我不想唱。”

　　You’d better sing an English song if they ask you (to) again.如果他們再要求你，你最后唱一首英文歌。

　　后面常省略不定式而保留to的結(jié)構(gòu)，還有：

　　used to   常常 be going to 打算

　　mean to  打算 ought to   應(yīng)該

　　plan to 計(jì)劃 want to     要想

　　(十)兩個(gè)不定式由and, or, except, but, than 連接時(shí)，第二個(gè)可省略to，尤其是兩個(gè)不定式緊密相連時(shí)。例如:

　　I intend to call on him and discuss this question again. 我打算去拜訪他并和他談?wù)勥@個(gè)問題。

　　I’d like to lie down and go to sleep. 我想躺下睡覺。

　　You’re free to talk or laugh here. 在這里你可以隨便說笑。

　　I’m anxious to go and ask him about it. 我急于去問問他這個(gè)事。

　　Do you want to have lunch now or wait till later?   你想現(xiàn)在吃午飯還是再等會兒?

　　We had nothing to do except (to) look at the posters outside the cinema. 我們無事可做，只有看看電影院外面的招貼。

　　He had nothing to do except talk nonsense.   除了胡說八道，他沒別的事干。

　　I would rather die than be insulted. 我寧死也不受侮辱。

　　I’ll do anything but work on a farm.   除了去農(nóng)場干活，我什么都干。

　　It’s easier to persuade people than (to) force them. 說服人容易，強(qiáng)迫人難。

　　It’s better to take a taxi than (to) wait here. 搭出租車也比在這等強(qiáng)。

　　句子中but后面的不定式帶不帶to，取決于but前面的句子里含不含do，只要有與do/did有關(guān)的詞(do作謂語，to do作定語等等)，but后面的不定式就省掉to。例如：

　　I can do nothing but go there alone. 除了獨(dú)自一個(gè)到那里去，我別無選擇。

　　I have nothing to do but go there alone. 除了獨(dú)自一個(gè)到那里去我沒事可干。

　　He did nothing but cry all day long. 他除了整天哭，什么也不干。

　　Now let’s do some exercises:

　　1.用動詞不定式結(jié)構(gòu)完成下列句子：

　　1)Let’s _______ (早回家). → go home early

　　2)I am going _____ (問問題). → to ask some questions

　　3)I’ve been hoping ______ (會見格林先生)ever since I left school → to see Mr. Green