不定式和分词表示原因的区别表示原因时，分词短语常放在句首，也可放在句未，多用逗号隔开；不定式短语却只能放在句末，但不用逗号，且多用于表示情绪或情感反应的动词、形容词(如happy, glad, sorry, sad, surprised, frightened, delighted, disappointed)之后。如：1. I’m surprised to see you here. 在这时遇到你真让我感到意外。2. ________ by the beauty of nature, the girl from London decided to stay another two days off the farm. (辽宁卷)A. AttractingB. AttractedC. To be attracted　D. Having attracted【分析】答案选B。在句首表示原因不能用不定式，排除C；句子主语the girl与attract是被动关系，用过去分词短语作原因状语。3. ________ in thought, he almost ran into the car in front of him. (全国卷)A. Losing B. Having lost C. Lost D. To lost【分析】答案选C。表示原因不能用不定式，排除D；句子主语he与lose是逻辑上是被动关系，用过去分词: Lost in thought…=As he was lost in thought… 此处的过去分词实际上是表示状态的形容词，用汉语思维难于理解，除be lost in thought(沉思)外，这类惯用结构还有be caught in the rain(遇到雨), be dressed in red(穿着红衣), be seated in a chair(坐在椅子上)等，并注意这类结构作补语或后置定语时也要用过去分词。4. ________ his telephone number, she had some difficulty getting in touch with Bill. (上海卷)A. Not knowing B. Knowing notC. Not having knownD. Having not known【分析】答案选A。现在分词的否定式在前面加not，“不知道电话号码”与“难与Bill联系”同时发生的不用完成式。Not knowing…=As she didn’t know…

　　说明:引用此文请注明出处,并请保留该文章链接地址,谢谢~~