<p>Normally, a "piece" of business, 事, is represented by 一件事. This could represent a contract, deal, or whatever.</p>

<p>But in this case, the "business" is a car accident, i.e. an action. 件 doesn't work as a modifier in this instance. You need an "action" modifier like 回, which roughly means "to come and go."</p>

CC BY-SA 3.0
2012-01-19T21:18:58.643Z
I doubt it. “昨天他开车的时候，头撞了一下。这(件)事不要告诉老王。” Here you can omit "件", but you cannot use "回".
fefe
CC BY-SA 3.0
2012-01-19T19:06:59.667Z
2012-01-19T19:06:59.667Z
Tom Au
<p>There are only a few phrases made up from 回事:</p>

<p>怎么(一)回事: what the matter with ..., why ..., what is the reason for ..., what happened</p>

<p>这回事: The matter you just mentioned (E.g 没这回事。 There was no such thing)</p>

<p>一回事: The same. (E.g. A和B是一回事。 A and B are the same (matter).)</p>

<p>In the above situations, "件" cannot be used.</p>

CC BY-SA 3.0
2012-01-19T02:22:24.290Z
This may not be very precise ...
fefe
CC BY-SA 3.0
2012-01-19T03:36:55.107Z
+1 and Chinese doesn't need to be very precise.
Dante WWWW
CC BY-SA 3.0
2012-01-19T02:22:02.497Z
2012-01-19T02:22:02.497Z
fefe
<p>In this dialogue:</p>
<blockquote>
<p>A: 昨天他开车的时候，头撞了一下。</p>
<p>B: 怎么一回事?</p>
</blockquote>
<p>Why is the classifier 回 used instead of 件?</p>

CC BY-SA 3.0
2012-01-19T18:00:41.180Z
i think the whole sentence will sound more smooth to add 儿 at the end...otherwise it's pretty hard to say even for a native chinese :)
Laguna
<measure-word>
Why 回 is used in 回事 instead of 件事?
# Why 回 is used in 回事 instead of 件事?

(Asked by: username_0 on 2012-01-19)

In this dialogue:

> A: 昨天他开车的时候，头撞了一下。
>
> B: 怎么一回事?

Why is the classifier 回 used instead of 件?

**Tags:** measure-word

> **Comments:**
> **username_1**: i think the whole sentence will sound more smooth to add 儿 at the end...otherwise it's pretty hard to say even for a native chinese :)  

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## 2 answers

### Answer by username_3 on 2012-01-19. Score: 5 | Accepted answer

There are only a few phrases made up from 回事:

怎么(一)回事: what the matter with ..., why ..., what is the reason for ..., what happened

这回事: The matter you just mentioned (E.g 没这回事。 There was no such thing)

一回事: The same. (E.g. A和B是一回事。 A and B are the same (matter).)

In the above situations, "件" cannot be used.

> **Comments:**
> **username_3**: This may not be very precise ...  
> **username_4**: +1 and Chinese doesn't need to be very precise.  

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### Answer by username_2 on 2012-01-19. Score: 0

Normally, a "piece" of business, 事, is represented by 一件事. This could represent a contract, deal, or whatever.

But in this case, the "business" is a car accident, i.e. an action. 件 doesn't work as a modifier in this instance. You need an "action" modifier like 回, which roughly means "to come and go."

> **Comments:**
> **username_3**: I doubt it. “昨天他开车的时候，头撞了一下。这(件)事不要告诉老王。” Here you can omit "件", but you cannot use "回".  

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