■ (to) do it 与 do so 简化为 to

1) 本来动词不定式 to do it 或 to do so 已经是一个简化了的说法，用来代替前面某处出现过的一个实义动词。但是，如果它放在另一个表示主观意向或处境的动词后面，还可以更进一步简化为单独的一个 to。这类主观意向或处境的动词，包括例如：hate, hope, intend, would like, love, mean, plan, tell, try, want, have, need, used (to), be able (to), be going (to)，等等。

• We only fail if we choose to (= we choose to do so = we choose to fail).我们唯有自己选择失败的时候才会失败。
• —Would you like to come with me?—Yes, I'd love to (= I'd love to do so = I'd love to go with you). —您跟我一起去好吗？—好的，我很乐意。
• — Did you get a ticket?—No. I tried to (= I tried to do so = I tried to get a ticket), but there weren't any left. —您弄到票吗？—没有。我设法要弄，但是没有剩的了。
• —Do you swim?—Not now but I used to (= I used to do so = I used to swim). —您游泳吗？—现在不游了，但是从前常游。
• He wanted to go but he wasn't able to(= he wasn't able to do so = he wasn't able to go).他本来想去，但没有能够去。
• —Why aren't you writing something? —I'm trying to (= I'm trying to do so = I'm trying to write something). —你写点东西也好嘛。—我正在打算写。
• —Are you and Jennifer getting married?—We hope to (= We hope to do so = We hope to get married). —你和詹妮弗要结婚了吧？—我们想这样

（注意：hope to 是自己打算做某事，hope so 是希望客观事态如何发展）。

• —Let's go for a walk. —I don't want to (= I don't want to do so = I don't want to go for a walk). —咱们去散散步吧。—我不想去。
• Things pass, whether you want them to (= to do so = to pass) or not.事情总是要过去的，不管你想不想它过去。
• —Why? —Because I told you to (= Because I told you to do so). —为什么？—因为我叫了你这样做的。
• He'll do it for you if you ask him to (= to do so = to do it for you).你如果请他给你做，他一定会做。
• He hoped he would not have to (= to do so).他希望不必做到这一步。
• I can't speak French yet, but I hope I will be able to (= to do so = to speak French) soon.我还不能讲法语，但是我希望不久之后就能够。
• Sorry I shouted at you. I didn't mean to (= I didn't mean to do so = I didn't mean to shout at you).对不起我对您喊叫了。我不是有意的。
• —Somebody ought to clean up the bathroom. —I'll ask John to (= I'll ask John to do so = I'll ask John to clean up the bathroom). —要有人来清扫一下洗澡间。—我去叫约翰干。
• She won't go, not even if we beg her to (= to do so = to go).咱们就是求她，她也不会去的。
• The people he was killing in Vietnam did not look like the enemy was supposed to (= was supposed to look like).他在越南杀死的人，并不像是敌人本来应有的那个模样。
• Most working mothers, the Census Bureau reports, are back in the workforce within a year of having a child; better educated women and those who can afford to drop out are actually less likely to (=to be back in the workforce). (Time, July 20, 2009, p.68)普查局报告说，职业妇女大多数在生了孩子后一年之内恢复参加工作；教育程度较高的妇女以及负担得起脱产的，则实际上比较不会这样做。
• And because Clinton did it then, Obama doesn't have to (= have to do it) now.(Times, May 26, 2008, p.35)而由于克林顿当时这样做了，奥巴马现在就用不着这样做了。
• He was working in Los Angeles, but I felt the distance between us was shrinking. I wanted it to (= I wanted it to be = I wanted it to be shrinking) and hoped he did too.他在洛杉矶工作，但是我觉得我们之间的距离在缩短。我很想如此，也希望他也这样想。

美国弗吉尼亚理工大学 2007 年 4 月枪击案后，5 月 11 日举行毕业典礼，一个遇害学生的父母还是来参加，说：

• We have to. This is right for us.我们应该来。这对来说我们是应该的。

有些名词后面也可以用 to 代替一个 to do so。

• He had reason to (= He had reason to do so).他有理由这样做。
• Most patrons don't smoke, but the outside area gives smokers a place to (= a place to do so = a place to smoke).大多数就餐的顾客不抽烟，但是室外区可以让抽烟者有地方抽烟。
• If there's need to (= need to do so = need to call me) you can call me.如果有需要，你可以打电话给我。

但是要注意两点。第一，必须本来已经是 to inf. 的形式，如果是其他动词形式，例如变位动词 (finite verb) 或是动词现在分词 (-ing)，本来就没有 to，当然不能用 to 来代替。第二，这个 to inf. 的不定式动词，如果不是有意识的主动动作，就不可以用 to 来代替，例如：表示“存在”或“被动”的 to be，表示“（非主动）占有”的 have，在 to 后面都不能省略为 to。

• He is nice only when he has to be (*has to).他唯有不得已的时候才对人亲切。
• There are more cars than there used to be (*used to).车子比从前多。
• She hasn't been promoted yet, but she ought to be (*ought to).她还没有得到提拔，但是她应该得到提拔。
• You've got more freckles than you used to have (*used to).你的雀斑比从前多了。

2) 有时候如果 to 前面有否定词 not，则连 to 也可以省略。

• Mel was tempted to laugh, then supposed he had better not (= not to = not to do so).梅尔真想笑起来，但是又觉得最好别笑。