语法为表达服务。
现在完成式（Present Perfect Tense）
| Just | Yet | Still | Already | |
|---|---|---|---|---|
| 意思 | 刚刚、刚好、刚才 | 还未完成 | 原本预计内应该要完成，但还未完成 | 已经完成，比预期内提早完成 |
| 位置 | 放在助动词 Have 与动词之间 | 句末 | 句中 | 放在助动词 Have 与动词之间 |
| 语气 | – | 中立 | 批判 | – |
| 否定型 | – | ✓ | ✓ | – |
| 例句 | I have just handed in my homework. (我刚刚递交了功课。) | I have not yet handed in my homework. (我还未递交功课。) (暗藏意味：尚未完成某些事，也不知道什么时候会完成，时间点比较模糊) | I still have not handed in my homework. (我仍然未递交功课。) (暗藏意味：期限已经过了，但是我还是没有交功课。) | I have already handed in my homework. (我已经递交了功课。) (暗藏意味：我在限期前交了功课。) |
不定式
表结果
- I hurried to the railway station to find my train is gone.
✔️ 我匆忙地赶到火车站（结果）却发现我的车已经出发了。
❌ 我匆忙地赶到火车站，是为了发现我的车已经走了（目的）。 - 🌰 A Pittsburgh-area woman with car trouble popped the hood of her vehicle to find squirrels had hidden more than 200 walnuts in the car's body.
- 🌰 He survived to see the end of the war.
特殊结构
- She was the only person to survive the air crash.
