感官動詞或使役動詞使用省略to的動詞不定式,主動語態中不帶to ,但變為被動語態時,須加上to . 例：make somebody do something→somebody+ be +made to do something see somebody do something→somebody +be +seen to do something A girl saw my wallet drop when she passed by.→My wallet was seen to drop by a girl when she passed by. The boss made the little boy do heavy work.→The little boy was made to do heavy work by the boss.

不帶to的動詞不定式作賓語補足語的主動語態改為被動語態時，省略的to要加上。

常考的動詞有make，let，have，see，watch，notice，hear等。

被動語態還原to的口訣：一感二聽三讓四看半幫助。這些詞包括feel，hear，listen to，make，have，let，see，watch，look at，observe，notice，help等。