区别：过去进行时强调过程，不一定完成；一般过去时强调事件，一定完成。过去进行时表示在过去某一特定的时间点或时间段正在进行的动作，一般过去时表示在过去时间完成的动作。
过去进行时和过去式怎么区分
1）过去进行时和一般过去时的基本差别是，过去进行时表示一个正在进行的动作，而一般过去时表示一个业已完成的动作。
试比较下面的句子：
She was knitting a sweater for Tom.她在给汤姆织一件毛衣。
She knitted a sweater for Tom.她给汤姆织了一件毛衣。
He was doing his homework in the afternoon.下午他在做作业。
He did his homework in the afternoon.下午他把作业做完了。
I was writing an essay.我在写一篇论文。（可能还没写完）
I wrote an essay yesterday.我昨天写了一篇论文。（已写完）
They were building a skyscraper.他们在建一座摩天大楼。（在修建）
They built a skyscraper.他们盖了一座摩天大楼。（已盖好）
2）有些动词本身并不表示动作完成，如rain,snow,cough,wear,feel,wait,stay,work等，这时用两种时态意思上差别不大：
It snowed all night.下了一整夜的雪。
It was snowing all night.
She wore a blue coat.她穿着一件蓝外套。
She was wearing a blue coat.
He felt a bit uneasy.他感到有点不自在。
He was feeling a bit uneasy.
We stayed in a hotel.我们住在旅馆里。
We were staying in a hotel.
3）用进行时态有时有感情色彩，特别是带有always,forever,constantly这类状语时，如：
He was always ringing up.他总是给我打电话。（厌烦）
She was always working.她总是不停地干活。（赞扬）
The old lady was forever grumbling.这老太太老是嘀嘀咕咕。（厌烦）
He was constantly changing his mind.他总是改变主意。（不以为然）
4）有时用进行时表示现在的想法，可以显得客气一点，如：
I was wondering whether you could give me some advice.不知你能否帮我出点主意。
I was thinking maybe he could go by taxi.我在想或许他可以坐的士去。
I was hoping you could reconsider our proposal.我希望你能再考虑一下我们的建议。
过去进行时和过去将来时的区别
过去进行时：表示过去正在进行的句子
结构：一般由be动词的过去式+现在分词
We were having supper when the phone rang.
过去将来时：表示在过去的一个点上还没发生的事
结构：主语+be（was，were）going to+动词原形+其他
主语+would（should）+动词原形+其他
He said he would come back the next day.他说他第二天回来。
动词的过去式和过去分词的变化规则
1、一般在动词原形后加-ed原形。
例：look;looked;looked，call;called;called
注意：-ed在清辅音音素后发音为[t]，在浊辅音后发音为[d]，在元音后发音也为[d]，-ed在[t]、[d]后发音为[id]needed[ni:did].
2、以-e结尾的动词直接加-d。
例：move;moved;moved，phone;phoned;phoned
3、以辅音字母加y结尾的动词，变y为i，再加-ed。
例：study;studied;studied
4、以元音字母加y结尾的词，直接加-ed。
例：play;played;played
5、末尾只有一个辅音字母的重读闭音节词，双写该辅音字母，再加-ed。
例：stop;stopped;stopped
