<blockquote>
<p>我想退了这件新买的毛衣。</p>
</blockquote>
<p>Semantically, 我想 itself connotes a <em><strong>completion</strong></em> already because when you say it you already think about it.  So we don't need 了 after 想 for completion.  That's why the sentence in title is not correct.</p>
<p>退了 denotes <em><strong>I want the action 退 get done</strong></em>. &quot;Done&quot; is for completion, so we need a 了 after 退.</p>
<p>P. S.  I somehow agree with you Chinese language is easier to learn if you focus more on logic, convention and culture, especially for second language learners.  Chinese grammar is the hardest part of the language. Only few people <em><strong>truly</strong></em> master Chinese grammar. Second language learners can easily create a wrong/stilted sentence based on the grammar rules they learned.</p>

CC BY-SA 4.0
2020-09-12T13:39:53.950Z
would 想过 be viable?
小奥利奥
CC BY-SA 4.0
2020-09-12T13:56:20.497Z
@小奥利奥 Yes, but it will change the meaning. 我想过退了这件新买的毛衣 implies you considered to 退了这件新买的毛衣, but for some reason you actually haven't 退.
dan
CC BY-SA 4.0
2020-09-11T23:17:44.993Z
2020-09-11T23:56:18.747Z
2020-09-11T23:56:18.747Z
dan
<p>Thought is not instantaneous.<br />
汤姆想了很久。<br />
Tom thought for a long time.<br />
温迪想了一会儿。<br />
Wendy thought for a while.<br />
Thought can take a while.<br />
这三只羊想了想。<br />
了 may indicate repetitive action<br />
他想了很多。<br />
He thinks a lot.</p>
<p>Thoughts, ideas, have almost no existence, but they are the most powerful things.</p>
<p>In your case: 想 = 想要：want</p>
<p>want is a desire, but the thing you want has not happened or come to you, or you would not need to &quot;want&quot; it.</p>
<p>想 = 想要 is on-going, in no sense &quot;complete&quot; and not repetitive. 了 has a meaning &quot;finished&quot;.</p>
<p>我想退这件新买的毛衣。(No 了)<br />
I want to return the sweater that I just bought.<br />
(You have not yet returned it, but you &quot;want&quot; to return it.)</p>
<p>&quot;了&quot; 有表示过去时，现在进行时，将来时的意思。</p>
<p>我想退了这件新买的毛衣。<br />
I want to return the pullover that I just bought.<br />
(You have not yet returned the pullover.)</p>
<p>我本来想退了这件新买的毛衣，但是现在我想留着它。<br />
I wanted to return the pullover I just bought, but now I want to keep it.</p>

CC BY-SA 4.0
2020-09-12T06:07:57.987Z
2020-09-12T06:07:57.987Z
Pedroski
<p>The correct sentence is &quot;我想退了这件新买的毛衣。&quot;  But why?
Please do not use grammar jargon because I seldom understand them.
I have been teaching Mandarin with grammar included but never mention and grammar term in my teaching and even the word &quot;grammar&quot; itself, simply because I am a victim of (English) grammar: hours spent just to memorize those stupid names, mind you, both in English and Chinese and their function/usage.
Instead, I use &quot;logic&quot; to teach grammar because Chinese is one of the most logical and cultural language in the world.</p>

CC BY-SA 4.0
2020-09-11T22:34:49.817Z
As long as you do write, you must follow the grammar rule, and grammar rules are base on a set of logic, e.g. adjective modifies the noun, an adverb modifies adjective and verb, and so on. To explain why a certain word must be placed in a certain part of a speech without explaining what grammar rule we are following is irresponsible
Tang Ho
<grammar><usage>
Why "我想了退这件新买的毛衣。” is wrong?
# Why "我想了退这件新买的毛衣。” is wrong?

(Asked by: username_0 on 2020-09-11)

The correct sentence is "我想退了这件新买的毛衣。" But why?
Please do not use grammar jargon because I seldom understand them.
I have been teaching Mandarin with grammar included but never mention and grammar term in my teaching and even the word "grammar" itself, simply because I am a victim of (English) grammar: hours spent just to memorize those stupid names, mind you, both in English and Chinese and their function/usage.
Instead, I use "logic" to teach grammar because Chinese is one of the most logical and cultural language in the world.

**Tags:** grammar, usage
> **Comments:**
> **username_1**: As long as you do write, you must follow the grammar rule, and grammar rules are base on a set of logic, e.g. adjective modifies the noun, an adverb modifies adjective and verb, and so on. To explain why a certain word must be placed in a certain part of a speech without explaining what grammar rule we are following is irresponsible  

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## 2 answers

### Answer by username_2 on 2020-09-11. Score: 1

> 我想退了这件新买的毛衣。

Semantically, 我想 itself connotes a ***completion*** already because when you say it you already think about it. So we don't need 了 after 想 for completion. That's why the sentence in title is not correct.

退了 denotes ***I want the action 退 get done***. "Done" is for completion, so we need a 了 after 退.

P. S. I somehow agree with you Chinese language is easier to learn if you focus more on logic, convention and culture, especially for second language learners. Chinese grammar is the hardest part of the language. Only few people ***truly*** master Chinese grammar. Second language learners can easily create a wrong/stilted sentence based on the grammar rules they learned.

> **Comments:**
> **username_3**: would 想过 be viable?  
> **username_2**: @小奥利奥 Yes, but it will change the meaning. 我想过退了这件新买的毛衣 implies you considered to 退了这件新买的毛衣, but for some reason you actually haven't 退.  

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### Answer by username_4 on 2020-09-12. Score: 0

Thought is not instantaneous.  
汤姆想了很久。  
Tom thought for a long time.  
温迪想了一会儿。  
Wendy thought for a while.  
Thought can take a while.  
这三只羊想了想。  
了 may indicate repetitive action  
他想了很多。  
He thinks a lot.

Thoughts, ideas, have almost no existence, but they are the most powerful things.

In your case: 想 = 想要：want

want is a desire, but the thing you want has not happened or come to you, or you would not need to "want" it.

想 = 想要 is on-going, in no sense "complete" and not repetitive. 了 has a meaning "finished".

我想退这件新买的毛衣。(No 了)  
I want to return the sweater that I just bought.  
(You have not yet returned it, but you "want" to return it.)

"了" 有表示过去时，现在进行时，将来时的意思。

我想退了这件新买的毛衣。  
I want to return the pullover that I just bought.  
(You have not yet returned the pullover.)

我本来想退了这件新买的毛衣，但是现在我想留着它。  
I wanted to return the pullover I just bought, but now I want to keep it.


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