核心问题
v-ed分词常被叫做被动分词，而为什么有的v-ed分词并无被动含义，例如fallen leaves?
词典解答
凡是由不及物动词变来的 v-ed 分词,都没有被动含义,而只有“完成”含义,这是它跟 v-ing 的不同之处,如 return→returned(father), grow→grown(boy), escape→escaped(prisoner), fall→fallen(leaves):
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The fallen player was helped to his feet. (FWF) 那位跌倒的运动员有人帮他站了起来。
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A grown man like you shouldn't act like that. (LDCE) 像你这样的成年人不应该有那种举动。