【练习】
1. I am sorry ______ written you a letter at the time.
A. to have not B. to not have C. not to have D. not having答案： C
解析： 不定式的完成式的否定式做原因状语，否定词not必须在不定式之前。
2. She had no money______ a birthday present for her children.
buy with which to buy
答案： D
解析： 介词＋关系代词＋不定式的结构可以在句中用作定语，其作用相当于一个定语从句。9.B。本题考查非谓语动词作定语。不定式作定语时，表示将来的动作；现在分词作定语,表示主动、进行；过去分词作定语，表示被动、完成。因为dates是被标在gold coin上，所以用过去分词表示被动。
3. Tom apologized to me ______ again.
A. to be late B. of being late
C. to have been late D. for beinglate
答案： D
解析： apologize to sb. for sth./doing sth.为常见搭配.
4. ______ all my letters, I had a drink and went out.
A.Finished B.Having finished C.Finishing D.To finish答案： B
解析： 因finish这一动作发生在I had a drink and went out之前,所以必须用现在分词的完成式。
5. From the dates______ on the gold coin, it is conformed that it was made five hundred years ago.
g be marked been marked答案： A
解析： 不定式作目的状语。
6.The policeman came up to the lonely house with the door ____(open), ____(stand) there for a while and then entered it.（填空练习）
答案：open; stood
解析： with the door open是with 的复合结构，open 为形容词，表状态； stood与came，entered为并列关系,在句中作谓语。
【小知识】动词不定式可以作下列的状语
①目的状语： Every morning he gets up very early to read English.
为了强调不定式表示目的的作用，可在不定式前加in order to或so as to（以便或为了），但应注意in order to位于句首或句中均可，而so as to不能位于句首，如：She reads China Daily every day in order to (so as to) improve her English.
将表示目的的不定式置于句首，也可强调目的的作用，如：To master a foreign language, one must work hard at it.
②结果状语：They lived to see the liberation of their home town.他们活到亲眼见到了他们家乡的解放。
③too + 形容词或副词 + 动词不定式，表示“足能”的结果，如：You are old enough to take care of yourself now.