【notuntil用法】在英语学习中，“not...until”结构是一个非常常见的表达方式，用于强调某个动作或状态直到某个时间点才发生或改变。掌握这一结构对于提高英语表达的准确性和自然度非常重要。
一、基本用法总结
“not...until”结构的基本含义是：“直到……才……”，表示某一动作或情况在某个时间点之前没有发生，而在该时间点之后才发生。其结构为：
Not + 主语 + 动词 + until + 时间/条件
例如：
- I didn't go to bed until 10 p.m.
（我直到晚上10点才睡觉。）
- She didn't realize the truth until it was too late.
（她直到太晚才意识到真相。）
二、常见句型与用法对比
| 句型结构 | 中文解释 | 例句 |
| Not + 主语 + 动词 + until + 时间 | 直到某时间才…… | I didn't start my work until 8 a.m. |
| Not + 主语 + 动词 + until + 条件 | 直到某种条件满足才…… | He didn't leave until the meeting ended. |
| Not only...but also... not until... | 不仅……而且直到……才…… | Not only did she arrive late, but she didn't even come until after the party started. |
| It is not until... that... | 直到……才…… | It is not until 2020 that he finally decided to change jobs. |
三、注意事项
1. 时态一致性：主句和从句的时态要保持一致。
- 正确：I didn’t know the answer until he told me.
- 错误：I don’t know the answer until he told me.
2. 否定前置：通常“not”放在动词前面，不能放在“until”后面。
- 正确：She didn’t leave until 9 p.m.
- 错误：She left not until 9 p.m.
3. 强调句式：可用于强调句型“It is not until... that...”来突出时间点。
- 正确：It is not until today that I understand the problem.
- 错误：Today is not until I understand the problem.
四、实际应用示例
| 场景 | 句子 |
| 日常对话 | I didn’t call him until I saw his message. |
| 写作表达 | The project wasn’t completed until the last minute. |
| 新闻报道 | It wasn’t until the storm passed that the city could resume normal life. |
通过掌握“not...until”的用法，可以更准确地表达时间关系和逻辑顺序，使语言更加地道和自然。建议多结合具体语境进行练习，以提升理解和运用能力。