<p>Both seem correct。实用现代汉语语法 available free on the web （<a href="http://book.douban.com/subject/1091176/" rel="nofollow">http://book.douban.com/subject/1091176/</a>）has
a section titled ＂是。。。的＂句 pp。７６２－７８４ discussing both possibilities。
In the introductory
section 一，＂是。。。的＂句（一）的结构特点 there already are two examples （１），（３）with 的 at the end of the sentence，and two before the object as in the sentence in question， 
（２）我是在预售处买的票。
（４）今天中午我们是吃的饺子。</p>

CC BY-SA 3.0
2015-08-05T00:45:45.730Z
+1 for 实用现代汉语语法.  This is an outstanding grammar reference book
wpt
CC BY-SA 3.0
2015-08-06T08:00:06.593Z
遗憾地是，与上述答案相反，该课本不是免费提供的。
user6065
CC BY-SA 3.0
2014-09-22T13:19:20.617Z
2014-09-22T13:19:20.617Z
user6065
<p>We don't put <code>的</code> between <code>买</code> and <code>苹果</code> but end of sentence to say <code>When did you bought the apples?</code>.</p>

<p>Also you can say <code>苹果是什么时候买的？</code> to express <code>When were the apples brought?</code></p>

CC BY-SA 3.0
2014-09-22T12:21:11.057Z
The sentence above doesn't make sense...? It's from Rosetta Stone's example sentence...
Blaszard
CC BY-SA 3.0
2014-09-23T14:12:57.337Z
I am from Hong Kong and we don't usually say that here. We usually use Cantonese here more than Mandarin. That is what I was taught anyway.
Pete C.
CC BY-SA 3.0
2014-09-23T18:10:19.113Z
Thank you for the information. Although I've been learning about Mandarin, I'm more interested in Hong Kong, so it's good to know that.
Blaszard
CC BY-SA 3.0
2014-09-22T11:36:50.620Z
2014-09-22T11:36:50.620Z
Pete C.
<p>I've found the following sentence:</p>

<pre><code>你是什么时候买的苹果？
</code></pre>

<p>However, I'm convinced that this sentence should be <code>你是什么时候买苹果的？</code>.</p>

<p>Why does the sentence above require <code>的</code> <em>after</em> <code>买</code>? What purpose does it function for?</p>

CC BY-SA 3.0
2014-09-22T10:13:38.777Z
You can say 你什么买苹果？ so if you put 是 in it ,you need to change 买 to a nonfinite verb。I don't know Chinese grammar,though I'm a native speaker.
sfy
<word>
Why is 的 necessary in 你是什么时候买的苹果?
# Why is 的 necessary in 你是什么时候买的苹果?

(Asked by: username_0 on 2014-09-22)

I've found the following sentence:
你是什么时候买的苹果？

However, I'm convinced that this sentence should be 你是什么时候买苹果的？.
Why does the sentence above require 的 after 买? What purpose does it function for?

**Tags:** word
> **Comments:**
> **username_1**: You can say 你什么买苹果？ so if you put 是 in it ,you need to change 买 to a nonfinite verb。I don't know Chinese grammar,though I'm a native speaker.  

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## 2 answers

### Answer by username_2 on 2014-09-22. Score: 2

Both seem correct。实用现代汉语语法 available free on the web （<http://book.douban.com/subject/1091176/>）has
a section titled ＂是。。。的＂句 pp。７６２－７８４ discussing both possibilities。
In the introductory
section 一，＂是。。。的＂句（一）的结构特点 there already are two examples （１），（３）with 的 at the end of the sentence，and two before the object as in the sentence in question，
（２）我是在预售处买的票。
（４）今天中午我们是吃的饺子。

> **Comments:**
> **username_3**: +1 for 实用现代汉语语法.  This is an outstanding grammar reference book  
> **username_2**: 遗憾地是，与上述答案相反，该课本不是免费提供的。  

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### Answer by username_4 on 2014-09-22. Score: 0

We don't put `的` between `买` and `苹果` but end of sentence to say `When did you bought the apples?`.

Also you can say `苹果是什么时候买的？` to express `When were the apples brought?`

> **Comments:**
> **username_0**: The sentence above doesn't make sense...? It's from Rosetta Stone's example sentence...  
> **username_4**: I am from Hong Kong and we don't usually say that here. We usually use Cantonese here more than Mandarin. That is what I was taught anyway.  
> **username_0**: Thank you for the information. Although I've been learning about Mandarin, I'm more interested in Hong Kong, so it's good to know that.  

---

