过去式是动词的一种时态,用来表示动作或状态在过去某个时间发生或存在。它可以分为简单过去时、过去进行时、过去完成时和过去完成进行时等几种形式。
1. 简单过去时(Simple Past Tense):表示过去某个具体时间发生的动作或存在的状态。例如:
I visited the museum yesterday.(我昨天参观了博物馆。)
She studied English last week.(她上周学习了英语。)
2. 过去进行时(Past Continuous Tense):表示过去某个时间正在进行的动作。例如:
I was reading a book when you called.(你打电话的时候,我正在看书。)
They were watching TV at 8 o'clock last night.(昨晚8点他们正在看电视。)
3. 过去完成时(Past Perfect Tense):表示在过去某个时间之前已经完成的动作或存在的状态。例如:
I had finished my homework before the teacher arrived.(老师来之前,我已经完成了作业。)
By the time she was 18, she had learned five foreign languages.(到她18岁的时候,她已经学会了五种外语。)
4. 过去完成进行时(Past Perfect Continuous Tense):表示在过去某个时间之前一直在进行的动作,并强调动作的持续性。例如:
By the time he left, he had been working for 10 hours.(他离开的时候,已经工作了10个小时。)
She had been waiting for her friend for two hours when she finally arrived.(她朋友终于到来时,她已经等了两个小时。)
过去式在英语语法中非常重要,可以帮助我们表达过去发生的事情,以及过去动作或状态的时间关系。