【问】 The patient was warned____oily food after the operation.

A. to eat not B. eating not

C. not to eat D. not eating(全国高考英语试题，96)

我查英汉词典没有查到warn to do的用法。

【答】 英语里确实没有warn to do的用法，但是有warn sb.(not) to do的用法，上题是这一用法的被动语态：

The doctors warned the patient not to eat oily food after the operation. →The patient waswarned not to eat oily food after the operation.

下面是类似的实例：

1. I warned you not to buy that old car. (FWF)

我劝你不要买那辆旧汽车。

2. They were warned not to climb the mountain in such bad weather. (ALD)

有人劝诫他们不要在这么坏的天气去登那座山。