核心问题
（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?
词典解答
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, watch, 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 )