分詞構句的問題??????請英文高手入內

Question

分詞構拒不是要去主詞嗎???可是我的老師告訴我說除了表原因的since , beacuse
as 等一定要去除，其餘的連接詞亦可保留是真的嗎????

Answer 1

1. 主詞必須是相同的才可以去掉喔例如His father having died and he being only five years old, his mother had to leave him in the care of a relative and go up north to look for jobs. 由於他的父親過世，而且他才五歲，他媽媽不得不將他托給一個親戚照顧，之後北上找工作。這兩句話主詞不同,所以就沒有去掉了.2. 應該是沒有錯的連接詞and, but, because/so不必保留(因為句意很明顯)， 但連接詞after/before/when/while/as, since, until，as if可以保留。