【过去进行时的标志词】在英语语法中，过去进行时（Past Continuous Tense）用于描述在过去某一时刻或某段时间内正在进行的动作。为了准确判断一个句子是否使用了过去进行时，我们需要关注一些常见的“标志词”（signal words）。这些词语可以帮助我们识别动作发生的时间背景和动作的持续性。
以下是对过去进行时常见标志词的总结，并附有表格形式的清晰展示。
一、过去进行时的标志词总结
1. at that time
表示在某个特定时间点，动作正在进行。例如：“He was watching TV at that time.”
2. at this time yesterday
强调昨天同一时间发生的动作。例如：“They were having lunch at this time yesterday.”
3. at the moment
虽然“at the moment”通常用于现在进行时，但在过去时态中也可表示过去某一刻正在发生的事情。例如：“She was talking to her friend at the moment I called.”
4. while + 过去时的主句
“while”引导的时间状语从句常与过去进行时搭配，表示两个动作同时发生。例如：“I was cooking while she was cleaning.”
5. when + 过去时的主句
“when”引导的从句可以表示一个动作发生时另一个动作正在进行。例如：“He was sleeping when I arrived.”
6. last night / last week / last year
表示过去某个时间段内持续的动作。例如：“We were studying for the exam last night.”
7. from 8 to 10 o'clock yesterday
表示一个具体的时间段内进行的动作。例如：“She was working from 8 to 10 o'clock yesterday.”
8. all day / all morning / all evening
表示整个时间段内持续的动作。例如：“They were playing football all day.”
9. this time last week / month / year
表示过去某一时期相同时间点正在发生的事情。例如：“I was on vacation this time last year.”
10. just then / right then
表示动作刚刚发生时的瞬间状态。例如：“He was leaving just then.”
二、过去进行时标志词表格
| 标志词 | 用法说明 | 例句 |
| at that time | 在某一特定时间点 | He was reading a book at that time. |
| at this time yesterday | 昨天同一时间 | They were having dinner at this time yesterday. |
| at the moment | 某一时刻 | She was talking to her mother at the moment. |
| while + 过去时 | 同时发生的动作 | I was cooking while she was washing dishes. |
| when + 过去时 | 一个动作发生时另一个动作正在进行 | He was sleeping when I called. |
| last night / last week / last year | 过去某段时间 | We were preparing for the party last week. |
| from 8 to 10 o'clock yesterday | 具体时间段 | She was working from 8 to 10 o'clock yesterday. |
| all day / all morning / all evening | 整个时间段 | They were traveling all day. |
| this time last week / month / year | 过去同一时期 | I was in Paris this time last year. |
| just then / right then | 刚刚发生时 | He was leaving just then. |
通过掌握这些标志词，我们可以更准确地理解和运用过去进行时，使语言表达更加自然、地道。在写作或口语中，合理使用这些时间提示词，有助于增强句子的逻辑性和时间感。
