【问】 (1) They made him repeat the message.他们让他重述了这个口信。

(2) They had him repeat the message.他们让他重述了这个口信。

句(1)可以改写成被动句：

He was made to repeat the message.

句(2)能否也改写成被动句呢?

【答】 有若干动词可用在宾语+不带to不定式这一结构中，如have，let，make，hear，wat-ch，observe等。其中have，let不能用于被动式：

×I was had (to) repeat the message.

×The prisoner was let go home.

(参见let)