一、現(xiàn)在分詞短語作時(shí)間狀語有以下三種情況：
1．分詞動(dòng)作一發(fā)生,謂語動(dòng)作緊跟著發(fā)生,這時(shí)用現(xiàn)在分詞的一般式作時(shí)間狀語,其邏輯主語為句中的主語.常用的動(dòng)詞,如：hear,see,arrive,return,get to,look,open,close,leave,turn around,walk等,表示一個(gè)極短暫動(dòng)作.
此種情況可以換作on+動(dòng)名詞,表示相同的意思.譯作"一（剛）……就……".
此種情況也可以換作是when引導(dǎo)的時(shí)間狀語從句,該從句的動(dòng)詞多用一般過去時(shí)表示.如：
Hearing their teacher's voice,the pupils stopped talking at once.（= On hearing their teacher's voice… = When they heard their teacher's voice,the pupils…）一聽到教師的聲音,學(xué)生們立即停止講話.
2．謂語動(dòng)作發(fā)生在分詞所表示的動(dòng)作過程之中,則用when /while+現(xiàn)在分詞的一般式,分詞的邏輯主語為句中的主語.此種情況可以用in+動(dòng)名詞的一般式代替.
也可以換作when、while引導(dǎo)的時(shí)間狀語從句,該從句的謂語動(dòng)詞用進(jìn)行時(shí)態(tài).如：
Don't be careless when /while having an exam.= Don't be careless in having an exam.= Don't be careless when / while you are having an exam.考試時(shí)不要粗心.
注：此結(jié)構(gòu)中,不能用其他連接詞替換when或while.
3．分詞所表示的動(dòng)作完成之后,謂語動(dòng)作才發(fā)生,則要現(xiàn)在分詞的完成式,即having done的形式.分詞的邏輯主語應(yīng)是句中的主語.
這種情況可以用after+動(dòng)名詞的一般式表示.
這種情況也可以用after /when引導(dǎo)的時(shí)間狀語從句來替換,該從句的謂語動(dòng)詞用過去完成式.如：
Having finished his homework the boy was allowed to watch TV play.
After having finished his homework,the boy…
After /when he had finished his homework,the boy…