英语语法标志性词语是帮助识别句子时态、语态、语用功能等语法要素的关键词汇。以下是常见语法类别的标志性词语分类整理：
一、时态标志性词语
一般现在时 - 时间状语：every day, always, usually, sometimes, on weekdays
- 现在分词标志：now, at the moment
- 例：
- The cat sleeps every day.
一般过去时
- 时间状语：yesterday, last week, last month
- 动词形式：过去式（如walked, ate）
- 例：
- I visited the museum last weekend.
一般将来时
- 时间状语：tomorrow, next week
- 结构：will + 动词原形
- 例：
- We will travel to Japan next year.
现在进行时
- 时间状语：right now, currently, at the moment
- 结构：be动词（am/is/are）+ -ing形式
- 例：
- She is reading a book right now.
过去完成时
- 时间标志词：before, by the time of
- 结构：had + 过去分词
- 例：
- By the time we arrived, the movie had started.
现在完成时
- 时间标志词：already, just, so far
- 结构：have/has + 过去分词
- 例：
- I have finished my homework already.
二、语态标志性词语
被动语态
- 关键词：be动词（am/is/are/was/were）+ 过去分词
- 例：
- The letter was sent by my friend.
主动语态
- 通过动作执行者+动词原形+宾语构成
- 例：
- She writes a letter every day.
三、语用标志性词语
条件状语从句
- 连接词：if, unless
- 例：
- If it rains, we will cancel the picnic.
让步状语从句
- 连接词：although, even though
- 例：
- Although it was cold, we went for a hike.
结果状语从句
- 连接词：so...that, such...that
- 例：
- The cake was so delicious that I ate it all.
四、其他常见标志词
并列连词： and, but, or 转折连词
递进连词：moreover, furthermore
否定词：never, nowhere, nothing
这些标志性词语通过不同语境帮助构建复杂句子结构，理解其用法需结合具体语法场景。
