原则一、两个句子必须要用连词连接，如果没有连词连接，则需要用非谓语动词
例1. _________ many times, but he still couldn’t understand it.
A. Having been told B. Having told C. He had been told D. Though he had been told
例2._________ many times, he still couldn’t understand it.
A. Having been told B. Having told C. He had been told D. Though he had told
解析：例1中有连词but连接，表明前后都是句子，所以答案为C。
例2中后面是一个句子，而且没有连词，所以前面不是句子，应该用非谓语动词，根据句意此处为被动，所以答案为A。
原则二、不及物动词无-ed形式非谓语动词，及物动词有宾语时用-ing形式，无宾语时用-ed形式
例3. ____________ in the mountains for a week, the two students were finally saved by the local police.
A. Having lost B. Lost C. Being lost D. Losing
解析：lose为及物动词，现在后面没有宾语，所以用-ed形式，答案为B。
例4. __________, I really believe that I’d prefer not to make any change now.
A. Considered all the possibilities B. Taking all the possibilities into consideration
C. Taken all the possibilities into consideration D. Giving all the possibilities
解析：把。。。考虑进来结构为take sth into consideration，现在take后面有宾语all the possibilities，所以用-ing形式，答案为B。
原则三、being done 表示“正在被”，一般不作状语，只作定语。非谓语动词的完成时形式to have done或having done强调该动作发生在句子谓语动词之前
例5. __ to reach them on the phone, we sent an email instead.
A. Fail B. Failed C. To fail D. Having failed
解析：根据句意“我们没有打通电话，就给他们发了个邮件”，没有打通电话应该发生在发邮件之前，所以用having done，答案为D。
例6. Tim Bemers-Lee is generally considered _____ the World Wide Web, on which all the information is shared by all.
A. to have founded B. having founded C. founding D. to found
解析：根据句意，Tim Bemers-Lee创立万维网应该是过去的事情，而且be considered后面应该用动词不定式，所以应该用to have done，答案为A。
原则四、非谓语动词作定语时，表示将来用-to do，表正在进行用-ing，表示已经完成用-ed
例7. The play_____ next month aims mainly to reflect the local culture.
A.produced B.being produced
C.to be produced D.having been produced
解析：根据本题中的时间状语next month，可知the play将要于下月被创作出来，表将来应该用to do，所以答案为C。
例8.The trees _____ in the storm have been moved off the road.
A. being blown down B. blown down C. blowing down D. to blow down
解析：根据句意“被暴风雨刮倒的树已经从路上移走了”，树被刮倒是过去已经完成的动作，表已经完成用-ed形式，所以答案为B。
原则五、介词后跟-ing形式，可以在-ing前加逻辑主语
例9. The discovery of new evidence led to ______________.
A. the thief having been caught B. the thief to be caught
C. catch the thief D. the thief being caught
解析：本题led to中的to是介词，后面应该用-ing形式，the thief作-ing的逻辑主语，所以答案为D。
例10. At the beginning of class, the noise of desks ____ could be heard outside the classroom.
A. opened and closed B. to be opened and closed
C. being opened and closed D. to open and close
解析：本题the noise of中的of是介词，后面应该用-ing形式，desks作-ing的逻辑主语，所以答案为C。
原则六、-ing形式或to do可作主语或宾语，-ed形式则不可以
例11. ___________ in a heavy traffic jam is quite an unpleasant experience.
A. Caught B. Having caught C. Being caught D. To catch
解析：本题中is为系动词，前面应该作主语，用-ing形式，所以答案为C。
例12 ___twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.
A. Examining B. Examined C. Being examined D. Having been examined
解析：本题中is为系动词，前面应该作主语，用-ing形式，所以答案为C。
原则七、be+-ed+介词结构常可把be去掉保留-ed+介词做状语
例13Michael’s new house is like a huge palace, ______with his old one.
A. comparing B. compares C. to compare D. compared
解析：“和。。。相比较”结构为be compared with，现在做句子的状语，所以只保留非谓语动词，把动词be去掉，答案为D。
例14 _______ with a difficult situation, Arnold decided to ask his boss for advice.
A. To face B. Having faced C. Faced D. Facing
解析：“面对”结构为be faced with, 现在做句子的状语，所以只保留非谓语动词，把动词be去掉，答案为C。
原则八、非谓语动词作状语，其逻辑主语必须和句子主语保持一致，和句子主语构成主谓关系时用-ing形式，构成动宾关系是用-ed形式。其逻辑主语和句子主语不一致时，要在非谓语动词前加逻辑主语，构成独立主格结构
例15. ____ twice, the postman refused to deliver our letters unless we changed our dog.
A. Being bitten B. Bitten C. Having bitten D. To be bitten
解析：本题考查非谓语动词作状语，其逻辑主语应和句子主语the postman一致，the postman应该是被咬，所以答案为B。
例16._______ in the fields on a March afternoon, he could feel the warmth of spring.
A. To walk. B. Walking C. Walked D. Having walked
解析：本题考查非谓语动词作状语，其逻辑主语应和句子主语he一致, he 和walk应该是主动关系，所以答案为B。
例17. While watching television, __________.
A. the doorbell rang B. the doorbell rings
C. we heard the doorbell ring D. we heard the doorbell rings
解析：根据“非谓语动词作状语，其逻辑主语必须和句子主语保持一致”的原则，watching的逻辑主语应和后面句子主语一致，所以句子主语应为“we”，答案为C。
例18. The children went home from the grammar school, their lessons ____ for the day.
A. finishing B. finished C. had finished D. were finished
解析：本题没有连词，所以后面应用非谓语动词，the lessons是非谓语动词的逻辑主语，和非谓语动词构成独立主格结构。根据句意应是“被完成”，所以答案为B。
原则九、不定式做状语一般有两种：目的状语和出乎意料的结果状语(表示顺其自然的结果用-ing形式)。另外，某些形容词(表喜、怒、哀、乐)做表语后跟不定式可以表示原因
例19._____, you need to give all you have and try your best.
A Being a winner B To be a winner C Be a winner D Having been a winner
解析：根据句意“要想成为获胜者，你要付出所有，尽最大努力”，此处表目的，所以答案为B。
例20. The news reporters hurried to the airport, only _______ the film stars had left.
A. to tell B. to be told C. telling D. told
解析：本句句意为“记者们匆匆赶到机场，却被告知明星们已经走了”，表出乎意料的结果常常用only to do，所以答案为B。
例21. The glass doors have taken the place of the wooden ones at the entrance, ________ in the natural light during the day.
A. to let B. letting C. let D. having let
解析：本题句意为“玻璃门替换了木头门，自然光就进来了”，自然光进来时顺其自然的结果，所以用doing, 答案为B。
例22.How glad I am ___________ you!
A. seeing B. to see C. saw D. having seen
解析：本题是I am glad to see you 的感叹句形式，to see you 是原因状语，答案为B。
原则十、非谓语动词的否定原则是在非谓语动词前加not，有not to do, not doing, not having done, not to have done几种形式
例23______that he was in great danger, Eric walked deeper into the forest.
A. Not realized B. Not to realize C. Not realizing D. Not to have realized
解析：本题考查doing的否定形式not doing，答案为 C。
例24. What worried him most was ______ to visit his sick child.
A. his being not allowed B. his not being allowed
C. his not allowing D. having not been allowed
解析：本题考查being done的否定形式not being done; his 为not being done的逻辑主语，所以答
案为B。
例25. Sarah has decided ________ away on holiday this summer.
A. don’t go B. to not go C. not going D. not to go
解析：本题考查to do的否定形式not to do, 所以答案为D。