to可以是介词,也可以用来引导不定式,四级考试中对种类用法的考查也比较多.如：
① I have no objection _______ your story again.(2000.6)
A.to hear B.to hearing C.to having heard D.to have heard
② The traditional approach ____ with complex problems is to break down into smaller,more easily managed problems.(1996.6)
A.to dealing B.in dealing C.dealing D.to deal
③ The man in the corner confessed to _____ a lie to the manager
of the company.(1997.6)
A.have told B.be told C.being told D.having told
这类考题的考查方式有两种,一是四个选项中有两个相对的选项to do something 和 to doing something,这时考查的自然是to的性质；另一种是to在题干中,如③.
