to可以是介詞,也可以用來引導不定式,四級考試中對種類用法的考查也比較多.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
這類考題的考查方式有兩種,一是四個選項中有兩個相對的選項to do something 和 to doing something,這時考查的自然是to的性質(zhì)；另一種是to在題干中,如③.