有一读者问： see, hear等动词后应接“宾语+不带to的不定式”，但有时为何却可后接带to的不定式？
see, hear等动词后接带to不定式的情况一般有两种。一种见于被动结构，如：
(1)He was seen to go upstairs.
(2)Somebody was heard to cry.
(3)She was made to go.
另一种情况比较特殊，只出现在较文气的英语里，如：
(4)I saw her corral lips to move.
(5)Money makes the mare to go. （谚语）
(6)She felt her feet to be stone-cold on the floor. （有的语法家认为这种表状态的to be用得较多）
