<blockquote>
<p>为 <a href="http://www.cantonese.sheik.co.uk/dictionary/characters/466/" rel="nofollow noreferrer">http://www.cantonese.sheik.co.uk/dictionary/characters/466/</a></p>
<p>[3] [v] be; is; be equivalent to</p>
</blockquote>
<p>为 has many different meanings, &quot;is&quot; (是) is just one of them.</p>
<p>You can replace '为' with '是' if you are using it as 'is' in the context.</p>
<ul>
<li><p>报名截止日期为2月17日。(literary)</p>
</li>
<li><p>报名截止日期是2月17日。(colloquial)</p>
</li>
</ul>
<blockquote>
<p><em>Also, is there any case that 为 must be used, not just because of &quot;formal&quot;?</em></p>
</blockquote>
<p>You must use '为' instead of '是' when  '为' doesn't mean 'is' in the context.</p>
<p>For example:</p>
<ul>
<li><p>'为' in &quot;印刷术、火药、指南针、‌​纸统称为四大发明&quot; follows the verb 称(be called). '为' here is not equivalent to 'is' but '<strong>as</strong>'.</p>
</li>
<li><p>You cannot say &quot;印刷术、火药、指南针、‌​纸[统称<strong>是</strong>]古代中国四大发明&quot;</p>
</li>
<li><p>But you can say &quot;印刷术、火药、指南针、‌​纸, [<strong>为</strong>]古代中国四大发明&quot; or &quot;印刷术、火药、指南针、‌​纸[<strong>是</strong>]古代中国四大发明&quot;</p>
</li>
</ul>
<p>because [印刷术、火药、指南针、‌​纸] [<strong>is</strong>] [古代中国四大发明]</p>
<p><strong>EDIT:</strong></p>
<p>If it is a written announcement, no matter what the predicate is, you should use 为.</p>
<p>Posting '报名截止日期[是]2月17日' or '报名费用[是]成人二十元，老人和儿童半价' is considered bad vocabulary choice (using colloquial term when it should be literary)</p>
<p>If it is an oral conversation, no matter what the predicate is, you should use 是</p>
<p>Telling someone '报名截止日期[为]2月17日' or '报名费用[为]成人二十元，老人和儿童半价' is also considered bad vocabulary choice (using literary term when it should be colloquial)</p>

CC BY-SA 3.0
2018-01-26T20:26:40.813Z
Thanks but I meant 为 in the use of “is”. I know it is also used as “as” but it is not in the scope of my question. I updated it to make it clearer.
Blaszard
CC BY-SA 3.0
2018-01-26T22:04:07.250Z
If the meaning is 'is',  then using '为' is more literary and  using '是' is more colloquial. As I stated in my answer. They are interchangeable , as the two example sentences showed.
Tang Ho
CC BY-SA 3.0
2018-01-27T11:27:03.693Z
Yes I know it is. But my question is about the date (or number I think as well). Is there any difference if the predicate is a date or not, regarding which verb to use?
Blaszard
CC BY-SA 3.0
2018-01-27T13:21:52.533Z
See my edition at the bottom.
Tang Ho
CC BY-SA 3.0
2018-01-27T13:47:39.903Z
I see, thanks. But isn’t it OK to use 是 in a literary form? Almost all grammar books for a beginner actually use 是 and don’t introduce 为. I feel they don’t differentiate written and oral contexts...
Blaszard
CC BY-SA 3.0
2018-01-27T14:02:31.920Z
It is OK. to  use 是 in literary form, for example,  in written dialogue. But in an announcement, it is not a good choice of vocabulary; It is also OK. to use 为 in oral conversation if you are treating it like a quote or when you read from a written text.
Tang Ho
CC BY-SA 3.0
2018-01-26T19:59:00.123Z
2018-01-27T14:05:51.597Z
2020-06-17T09:50:11.587Z
Tang Ho
<p>Suppose that the following example:</p>

<blockquote>
  <p>报名截止日期<strong>为</strong>2月17日。</p>
</blockquote>

<p>In these cases that take a date as the predicate, I usually see 为 instead of 是. Both mean "is" and I already learned 为 is more formal than 是.</p>

<p>However, I feel I have only seen 为 if it takes a date on its predicate. So I wonder whether it must be 为 if you take a date as the predicate or it is just a coincidence. </p>

<p>Also, is there any case that 为 must be used in the usage of “is” or “be”, not just because of "formal"?</p>

CC BY-SA 3.0
2018-01-26T17:18:51.503Z
'为' in "印刷术、火药、指南针、‌​纸统称～四大发明" follows the verb 称(be called). It is not equivalent to 'is' but 'as'
Tang Ho
CC BY-SA 3.0
2018-01-26T21:21:12.333Z
"are called"  ("called as" ?)， "call sth sth"  example of "Double Accusative Construction", which may correspond "V+N+as+N" for some other verbs, "denominate sth. as sth (?)", in the present it might be argued that 为 in E corresponds to "nothing"
user6065
<verbs>
Should I use 为 instead of 是 to mean "is" on a date?
# Should I use 为 instead of 是 to mean "is" on a date?

(Asked by: username_0 on 2018-01-26)

Suppose that the following example:

> 报名截止日期**为**2月17日。

In these cases that take a date as the predicate, I usually see 为 instead of 是. Both mean "is" and I already learned 为 is more formal than 是.

However, I feel I have only seen 为 if it takes a date on its predicate. So I wonder whether it must be 为 if you take a date as the predicate or it is just a coincidence.

Also, is there any case that 为 must be used in the usage of “is” or “be”, not just because of "formal"?

**Tags:** verbs

> **Comments:**
> **username_1**: '为' in "印刷术、火药、指南针、‌​纸统称～四大发明" follows the verb 称(be called). It is not equivalent to 'is' but 'as'  
> **username_2**: "are called"  ("called as" ?)， "call sth sth"  example of "Double Accusative Construction", which may correspond "V+N+as+N" for some other verbs, "denominate sth. as sth (?)", in the present it might be argued that 为 in E corresponds to "nothing"  

---

## 1 answers

### Answer by username_1 on 2018-01-26. Score: 1 | Accepted answer

> 为 <http://www.cantonese.sheik.co.uk/dictionary/characters/466/>
>
> [3] [v] be; is; be equivalent to

为 has many different meanings, "is" (是) is just one of them.

You can replace '为' with '是' if you are using it as 'is' in the context.

* 报名截止日期为2月17日。(literary)
* 报名截止日期是2月17日。(colloquial)

> *Also, is there any case that 为 must be used, not just because of "formal"?*

You must use '为' instead of '是' when '为' doesn't mean 'is' in the context.

For example:

* '为' in "印刷术、火药、指南针、‌​纸统称为四大发明" follows the verb 称(be called). '为' here is not equivalent to 'is' but '**as**'.
* You cannot say "印刷术、火药、指南针、‌​纸[统称**是**]古代中国四大发明"
* But you can say "印刷术、火药、指南针、‌​纸, [**为**]古代中国四大发明" or "印刷术、火药、指南针、‌​纸[**是**]古代中国四大发明"

because [印刷术、火药、指南针、‌​纸] [**is**] [古代中国四大发明]

**EDIT:**

If it is a written announcement, no matter what the predicate is, you should use 为.

Posting '报名截止日期[是]2月17日' or '报名费用[是]成人二十元，老人和儿童半价' is considered bad vocabulary choice (using colloquial term when it should be literary)

If it is an oral conversation, no matter what the predicate is, you should use 是

Telling someone '报名截止日期[为]2月17日' or '报名费用[为]成人二十元，老人和儿童半价' is also considered bad vocabulary choice (using literary term when it should be colloquial)

> **Comments:**
> **username_0**: Thanks but I meant 为 in the use of “is”. I know it is also used as “as” but it is not in the scope of my question. I updated it to make it clearer.  
> **username_1**: If the meaning is 'is',  then using '为' is more literary and  using '是' is more colloquial. As I stated in my answer. They are interchangeable , as the two example sentences showed.  
> **username_0**: Yes I know it is. But my question is about the date (or number I think as well). Is there any difference if the predicate is a date or not, regarding which verb to use?  
> **username_1**: See my edition at the bottom.  
> **username_0**: I see, thanks. But isn’t it OK to use 是 in a literary form? Almost all grammar books for a beginner actually use 是 and don’t introduce 为. I feel they don’t differentiate written and oral contexts...  
> **username_1**: It is OK. to  use 是 in literary form, for example,  in written dialogue. But in an announcement, it is not a good choice of vocabulary; It is also OK. to use 为 in oral conversation if you are treating it like a quote or when you read from a written text.  

---

