介词加不定式的用法

介词通常后加名词形成介词短语（如, in school, before the war 等)，但介词也可以加不定式。这篇文章给大家归纳一下介词加不定式的用法。

1. 只有少数几个介词可以加不定式，包括 save, but, except, other than 和 than等。其中save, but, except 和 other than 都表示“除……之外”的意思。than 则用于表示比较。

1) but 除……以外
She had no alternative but to ask for a few days' leave. 她没有别的办法，只好请几天假。
We had no choice but to leave. 我们只好选择离开。

2) save 除……之外
What did she do save to talk nonsense? 她除了讲废话还会讲什么？
Do anything, save to lie down and die! 你做什么都可以，只要不倒下死掉！

3) except 除了……之外
She has no other wish except to pass the examination. 她除了要通过考试之外，没有其他心愿。
He never calls me except to borrow money. 除了借钱，他从来不给我打电话。

4) other than 除了……之外
There is no solution to this problem other than to obtain better tools. 除了获取更好的工具之外，没有其他办法可以解决这个问题。

4) than 表示比较，意为“而不是，而不该，与其”。
You should know better than to behave like that. 你应该明白事理，不该那样做。
It is better to marry than to burn. 与其欲火攻心，倒不如结婚为妙。

2. 这些介词后边的不定式可以是省列to的不定式，如：
He had nothing to do except watch TV at home. 除了看电视之外，他没有别的事情可做。
She'd sooner share a house with other students than live at home with her parents. 她宁愿和其他学生合住，也不愿意跟父母住在家里。 (注: would sooner...than 意思为“宁愿……而不愿……”）

3. 介词短语还可以有“介词 + 疑问词 + 不定式”的格式。这种情况中的“疑问词 + 不定式”部分语法上是一个名词性从句。

I couldn't think of where to buy the printer. 我不能想到去哪儿买打印机。
The problem of what to do is difficult to settle. 很难解决该做什么的问题。
That depends on which method to use. 这取决于所使用的方法。
This course solves a series of problems regarding how to sell your products. 本课程解决如何销售产品的一系列问题。