看该动词与句子主语之间的逻辑关系,如果是主谓关系用现在分词,如果是动宾即被动关系则用过去分词.当然,还有特殊情况,具体情况具体分析.例入：Watching the moive,he knows what true love is.(他看电影) Helped by the teacher,she understands the difficult sentence.(她被帮助).