表主动时 ,用现在分词。表被动时,用过去分词。如:
Weather permitting,they will go on an outing to the beach tomorrow.=If weather permits,they will go on an outing to the beach tomorrow.(如果天气允许的话,他们将在明天组织一次海滨小游。
My shoes removed,I entered a low-ceilinged room,treading cautiously on the soft tatami matting.=After my shoes were removed, I entered a low-ceilinged room,treading cautiously on the soft tatami matting.(我脱掉鞋子后,走进一间屋顶很低的房间,小心翼翼地踩在柔软的塌塌米垫子上。)
分词和逻辑主语是主动关系时,用现在分词普通式 doing
分词和逻辑主语是主动关系,且分词表示的动作比谓语表示的动作要早,用现在分词完成式 having done
分词和逻辑主语是被动关系,且分词表示的动作和谓语表示的动作同时进行(或者分词动作现在正在进行),用现在分词被动式 being done.
分词和逻辑主语是被动关系时,用过去分词 done