<p>了 never appears in past negation. </p>

<p>By definition, one of 了 grammatical functions is to indicate <strong>completed action</strong>, and not past tense. Hence, if the action did not happen at all (没), it has also never been <strong>completed</strong>. </p>

<blockquote>
  <p>他还没来 - He still didn't come (and not<code><s>他还没来了</s></code>）</p>
</blockquote>

<p>A side note to that is that 了 would appear in <strong>present</strong> negation. </p>

<blockquote>
  <p>他不来了 - He is not coming.</p>
</blockquote>

CC BY-SA 4.0
2019-10-03T10:02:08.317Z
2019-10-03T10:02:08.317Z
Yoav Vollansky
<p>regarding 了 and negation note e.g. <a href="http://human.bsru.ac.th/e-learning/@PWP%20to%20PDF/57%20PDF%20Chiness/57%20Chiness%20Nongnut%202104308.pdf" rel="nofollow noreferrer">http://human.bsru.ac.th/e-learning/@PWP%20to%20PDF/57%20PDF%20Chiness/57%20Chiness%20Nongnut%202104308.pdf</a> </p>

<p>3）否定句中</p>

<p>♥ 否定句中，“没”与“了”不能同时出现。</p>

<p>♥ 我吃完饭了。→我没吃完饭。→*我没吃完饭了。</p>

<p>♥ 注意：动词前有表示一段时间的词语，句末可用语
气助词“了”。</p>

<p>♥ 我好长时间没看到他了。</p>

<p>♥ 他好久没上班了。</p>

<p>♥ 一年多没回家乡了。</p>

<p>naturally still applies to conditional clauses corresponding to English past subjunctive mood 过去虚拟语气:if I had not bought that 要是我没（有）买这个 (w/o 了）
naturally 过 is possible (要是)我没（有）买过这个</p>

<p>to find more articles concerning absence of 了 in negative clauses search web using e.g. 汉语语法：动态助词＂了＂ 用法与意义＋否定句，get e.g. <a href="http://www.cim.chinesecio.com/hbcms/f/article/info?id=3c85e3090860428da0854f5fbab24aa5" rel="nofollow noreferrer">http://www.cim.chinesecio.com/hbcms/f/article/info?id=3c85e3090860428da0854f5fbab24aa5</a> : (三)否定句和疑问句</p>

<p>1.带有表示完成的“了”的句子的否定形式是没(有)+ 谓语动词注意：在用“没”的句子里,不可以再出现“了”。</p>

<p>2.问句比较容易,用“吗”的疑问句和正反疑问句。如：他写了三个汉字吗？</p>

<p>他写没写三个汉字？  </p>

<p>for English could google "Chinese grammar: aspect particle 了: negation"  get e.g. <a href="http://intensive-chinese.blogspot.com/2012/01/used-as-aspect-particle-and-as-modal.html" rel="nofollow noreferrer">http://intensive-chinese.blogspot.com/2012/01/used-as-aspect-particle-and-as-modal.html</a> (f) If you want turn an affirmative sentence which contains the aspect particle “了” into a negative sentence, you can do so by prefixing the adverb “没有” to the verb whilst dropping the aspect particle, e.g.:
       他      吃了 晚饭 就 去 看 电影。
       他 没有 吃   晚饭 就 去 看 电影。</p>

<p>We should never use “不” to negate a verb in the past tense or present perfect tense. For this purpose, we use  “没有”; and when using “没有” , we also drop “了” .  </p>

CC BY-SA 4.0
2019-04-04T08:14:18.280Z
Not sure how long it will take an English speaker to learn from something written in Chinese for Thai speakers.
伟思礼
CC BY-SA 4.0
2019-04-04T08:35:40.203Z
text does not seem to reveal that it might be addressed to Thai speakers, anyhow it states a well known fact that can easily be found in any grammar
user6065
CC BY-SA 4.0
2019-04-05T17:39:25.943Z
Easily?  Perhaps easy for Chinese speakers.  I assume it's directed at Thai speakers because it comes from Thailand and has some Thai in it.
伟思礼
CC BY-SA 4.0
2019-04-03T22:27:12.640Z
2019-05-05T08:27:32.300Z
2019-05-05T08:27:32.300Z
user6065
<p>Is 了 ever/sometimes/never omitted for past subjunctive?  What if not subjunctive; i.e., positively something did happen.</p>

<p>wohok.com gives for 没 two example sentences</p>

<pre><code>我没买这个
我没有买这个
</code></pre>

<p>and translates both as "I didn't buy this."  (Could argue this is not subjunctive, but I am familiar with languages where a negative is always subjunctive.</p>

<p>——————</p>

<p>Aside …</p>

<p><a href="https://chinese.stackexchange.com/questions/22524/what-is-the-difference-between-%E6%B2%A1%E6%9C%89v-and-%E6%B2%A1v">What is the difference between 没有+V. and 没+V.?</a> answers that there is no practical difference between 没有 and 没, but a comment suggests subtle differences in meaning or connotation.  (Have to translate a lot of Chinese to figure out what it is saying!) </p>

CC BY-SA 4.0
2019-04-04T07:03:39.857Z
Yes, one of my questions _was_ duplicate before edit, though it will take me time to understand.  (The duplicate suggester is almost never helpful; how do you guys find them?). The other question _remains_ after edit.
伟思礼
CC BY-SA 4.0
2019-04-05T00:17:29.613Z
I think the question is very good. The role of 了 in Chinese is strange to say the least. Generally, Chinese people I ask would not use '了' in '我没有买。' but they might end with '啊 or 呀' Cf. ‘我不（想）买了。’I don't （want） to buy (that, it). = I won't buy that.' You might say: '汉语好奇怪啊！‘ but not '汉语好奇怪了’！:)
Pedroski
CC BY-SA 4.0
2019-06-04T10:08:48.147Z
@伟思礼 What languages have negative = always subjunctive?
Michaelyus
CC BY-SA 4.0
2019-06-04T16:10:01.940Z
Well, maybe _usually_ subjunctive in Romance languages.
伟思礼
CC BY-SA 4.0
2019-11-07T09:06:05.407Z
It means Finished, or you idea changed.
Daniel Yang
<grammar><meaning>
"I didn't buy that" without 了
# "I didn't buy that" without 了

(Asked by: username_0 on 2019-04-03)

Is 了 ever/sometimes/never omitted for past subjunctive?  What if not subjunctive; i.e., positively something did happen.
wohok.com gives for 没 two example sentences
我没买这个
我没有买这个

and translates both as "I didn't buy this."  (Could argue this is not subjunctive, but I am familiar with languages where a negative is always subjunctive.
——————
Aside …
What is the difference between 没有+V. and 没+V.? answers that there is no practical difference between 没有 and 没, but a comment suggests subtle differences in meaning or connotation.  (Have to translate a lot of Chinese to figure out what it is saying!)

**Tags:** grammar, meaning
> **Comments:**
> **username_0**: Yes, one of my questions _was_ duplicate before edit, though it will take me time to understand.  (The duplicate suggester is almost never helpful; how do you guys find them?). The other question _remains_ after edit.  
> **username_1**: I think the question is very good. The role of 了 in Chinese is strange to say the least. Generally, Chinese people I ask would not use '了' in '我没有买。' but they might end with '啊 or 呀' Cf. ‘我不（想）买了。’I don't （want） to buy (that, it). = I won't buy that.' You might say: '汉语好奇怪啊！‘ but not '汉语好奇怪了’！:)  
> **username_2**: @伟思礼 What languages have negative = always subjunctive?  
> **username_0**: Well, maybe _usually_ subjunctive in Romance languages.  
> **username_3**: It means Finished, or you idea changed.  

---

## 2 answers

### Answer by username_4 on 2019-10-03. Score: 1

了 never appears in past negation.

By definition, one of 了 grammatical functions is to indicate **completed action**, and not past tense. Hence, if the action did not happen at all (没), it has also never been **completed**.

> 他还没来 - He still didn't come (and not`他还没来了`）

A side note to that is that 了 would appear in **present** negation.

> 他不来了 - He is not coming.


---

### Answer by username_5 on 2019-04-03. Score: 0

regarding 了 and negation note e.g. <http://human.bsru.ac.th/e-learning/@PWP%20to%20PDF/57%20PDF%20Chiness/57%20Chiness%20Nongnut%202104308.pdf>

3）否定句中

♥ 否定句中，“没”与“了”不能同时出现。

♥ 我吃完饭了。→我没吃完饭。→\*我没吃完饭了。

♥ 注意：动词前有表示一段时间的词语，句末可用语
气助词“了”。

♥ 我好长时间没看到他了。

♥ 他好久没上班了。

♥ 一年多没回家乡了。

naturally still applies to conditional clauses corresponding to English past subjunctive mood 过去虚拟语气:if I had not bought that 要是我没（有）买这个 (w/o 了）
naturally 过 is possible (要是)我没（有）买过这个

to find more articles concerning absence of 了 in negative clauses search web using e.g. 汉语语法：动态助词＂了＂ 用法与意义＋否定句，get e.g. <http://www.cim.chinesecio.com/hbcms/f/article/info?id=3c85e3090860428da0854f5fbab24aa5> : (三)否定句和疑问句

1.带有表示完成的“了”的句子的否定形式是没(有)+ 谓语动词注意：在用“没”的句子里,不可以再出现“了”。

2.问句比较容易,用“吗”的疑问句和正反疑问句。如：他写了三个汉字吗？

他写没写三个汉字？

for English could google "Chinese grammar: aspect particle 了: negation" get e.g. <http://intensive-chinese.blogspot.com/2012/01/used-as-aspect-particle-and-as-modal.html> (f) If you want turn an affirmative sentence which contains the aspect particle “了” into a negative sentence, you can do so by prefixing the adverb “没有” to the verb whilst dropping the aspect particle, e.g.:
他 吃了 晚饭 就 去 看 电影。
他 没有 吃 晚饭 就 去 看 电影。

We should never use “不” to negate a verb in the past tense or present perfect tense. For this purpose, we use “没有”; and when using “没有” , we also drop “了” .

> **Comments:**
> **username_0**: Not sure how long it will take an English speaker to learn from something written in Chinese for Thai speakers.  
> **username_5**: text does not seem to reveal that it might be addressed to Thai speakers, anyhow it states a well known fact that can easily be found in any grammar  
> **username_0**: Easily?  Perhaps easy for Chinese speakers.  I assume it's directed at Thai speakers because it comes from Thailand and has some Thai in it.  

---

