1．過(guò)去進(jìn)行時(shí)往往表示動(dòng)作的未完成性,而一般過(guò)去時(shí)往往表示動(dòng)作已完成.試比較：
David wrote a letter to his father last night．
大衛(wèi)昨晚給他父親寫了一封信.(信寫完了.)
David was writing a letter to his father last night．
大衛(wèi)昨晚正在給他父親寫信.(指信在寫的過(guò)程中,不一定寫完.)
2．過(guò)去進(jìn)行時(shí)和always連用,表示贊揚(yáng)、感嘆、厭惡等感情色彩；而一般過(guò)去時(shí)和always連用,表示經(jīng)?；蚍磸?fù)發(fā)生的動(dòng)作.試比較：
He was always changing his mind．
他總是三心二意.(表示厭惡)
He always went to work by bus last year．
去年他總是乘坐公共汽車上班.(表示經(jīng)常性動(dòng)作)
3．一般說(shuō)來(lái),過(guò)去進(jìn)行時(shí)側(cè)重動(dòng)作持續(xù)時(shí)間的長(zhǎng)度；而一般過(guò)去時(shí)只說(shuō)明過(guò)去某時(shí)發(fā)生某事,側(cè)重說(shuō)明事實(shí).試比較：
It was raining heavily last night．
昨晚下著大雨.(側(cè)重說(shuō)明下雨持續(xù)的時(shí)間長(zhǎng).)
It rained heavily last night．
昨天下了大雨.(側(cè)重說(shuō)明下雨這一事實(shí).)
4．在帶有all night,the whole morning等強(qiáng)調(diào)時(shí)間長(zhǎng)度的狀語(yǔ)時(shí),句中謂語(yǔ)動(dòng)詞用過(guò)去進(jìn)行時(shí)更好些.如：
He was working all night last Monday．
上周一他整整工作了一個(gè)晚上.
5．在when引導(dǎo)的時(shí)間狀語(yǔ)從句中,當(dāng)when相當(dāng)于while時(shí),用一般過(guò)去時(shí)與過(guò)去進(jìn)行時(shí)差異不大.如：
I saw John when I walked／was walking to the station．
我步行去火車站時(shí)看見了約翰.
但當(dāng)when分句中的謂語(yǔ)動(dòng)詞為一般過(guò)去,其主句用一般過(guò)去時(shí)或過(guò)去進(jìn)行時(shí),有時(shí)會(huì)引起時(shí)間關(guān)系的變化.試比較：
When we arrived,she was making some fresh coffee．
我們到達(dá)時(shí),她在調(diào)制咖啡.(分句動(dòng)作發(fā)生時(shí),主句動(dòng)作已在發(fā)生．)
When we arrived,she made some fresh coffee．
我們到達(dá)時(shí),她調(diào)制了咖啡.(分句動(dòng)作發(fā)生在主句動(dòng)作之前.)
6．有些表示狀態(tài)、感覺、心理或情感的動(dòng)詞,
如:be,have(有),see,hear,know,think,believe,understand等,一般不用過(guò)去進(jìn)行時(shí),而用一般過(guò)去時(shí).如：I had a lot of work to do yesterday．昨天我有許多工作要做.
參考資料：初中語(yǔ)法