<blockquote>
<p>要上山，只有这一条路。<br />
To go up the mountain, there is only this 1 road.</p>
</blockquote>
<p>Here, 一 is the number 1.  一条路 = &quot;one road&quot; (wherein 条 is a measure word).  So we could change it to any other number, e.g.:</p>
<blockquote>
<p>要上山，只有这六条路。<br />
To go up the mountain, there are only these 6 roads.</p>
</blockquote>
<p>Replacing 这一条路 with 这条路 above is fine: with <a href="https://resources.allsetlearning.com/chinese/grammar/Measure_word_%22ge%22#Omitting_the_Number" rel="noreferrer">the number omitted</a>, the default quantity is 1.</p>
<p>In 人的一生中, the 一 is part of the word:</p>
<blockquote>
<p>一生 (yī​shēng​)<br />
<a href="https://www.mdbg.net/chinese/dictionary?wdqb=%E4%B8%80%E7%94%9F" rel="noreferrer">CC-CEDICT</a>: all one's life / throughout one's life</p>
</blockquote>
<p>If we delete the 一 from the word 一生, we'd obtain <a href="https://www.mdbg.net/chinese/dictionary?wdqb=%E7%94%9F" rel="noreferrer">生</a> which is a completely different word.  So we can't delete the 一 here.</p>
<p>More generally:</p>
<ol>
<li><p>There are a bunch of words and idioms containing the character 一 (e.g. 一生, 一起, 一样, 一叶障目): by deleting the 一 from within a word, we'll almost always end up with nonsense.</p>
</li>
<li><p>There are a number of grammar structures that also use 一, such as <a href="https://resources.allsetlearning.com/chinese/grammar/Events_in_quick_succession_with_%22yi..._jiu...%22" rel="noreferrer">一……就……</a>.  Occasionally it's okay to omit the 一, such as how <a href="https://resources.allsetlearning.com/chinese/grammar/Simultaneous_tasks_with_%22yibian%22" rel="noreferrer">一边……一边……</a> is sometimes written 边……边…….  However, I'd guess for most grammar structures involving 一, it won't be okay to omit the 一.</p>
</li>
<li><p>It's often okay to omit the 一 before a <a href="https://resources.allsetlearning.com/chinese/grammar/Measure_word" rel="noreferrer">measure word</a>: 她是一个孩子 = 她是个孩子 but I don't think it's always okay to omit it: I wouldn't start a sentence with a measure word (e.g. I wouldn't write 一匹马在吃草 as just 匹马在吃草), and omitting it in 一个人 might result in confusion with the word <a href="https://www.mdbg.net/chinese/dictionary?wdqb=%E4%B8%AA%E4%BA%BA" rel="noreferrer">个人</a>.</p>
</li>
</ol>

CC BY-SA 4.0
2020-12-16T12:58:54.437Z
2020-12-16T12:58:54.437Z
Becky 李蓓
<p>I came across this sentence:</p>
<blockquote>
<p>要上山，只有这一条路</p>
</blockquote>
<h3>Is there a <em>rule</em> when to throw in a <code>一</code>?</h3>
<p>In detail:</p>
<ol>
<li>What exactly is the <strong>function</strong> of <code>一</code> in this sentence ?</li>
<li>Could I also simply say <code>要上山，只有这条路</code> ?</li>
</ol>
<p>Sometimes I come across some unexpected <code>一</code> like in this sentence:</p>
<blockquote>
<p>人的一生中，究竟什么是最重要的？</p>
</blockquote>
<p>Many thanks!!</p>

<usage><word>
What is the function of "一" in the sentence 要上山，只有这一条路?
# What is the function of "一" in the sentence 要上山，只有这一条路?

(Asked by: username_0 on 2020-12-16)

I came across this sentence:

> 要上山，只有这一条路

### Is there a *rule* when to throw in a `一`?

In detail:

1. What exactly is the **function** of `一` in this sentence ?
2. Could I also simply say `要上山，只有这条路` ?

Sometimes I come across some unexpected `一` like in this sentence:

> 人的一生中，究竟什么是最重要的？

Many thanks!!

**Tags:** usage, word


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## 1 answers

### Answer by username_1 on 2020-12-16. Score: 5 | Accepted answer

> 要上山，只有这一条路。  
> To go up the mountain, there is only this 1 road.

Here, 一 is the number 1. 一条路 = "one road" (wherein 条 is a measure word). So we could change it to any other number, e.g.:

> 要上山，只有这六条路。  
> To go up the mountain, there are only these 6 roads.

Replacing 这一条路 with 这条路 above is fine: with [the number omitted](https://resources.allsetlearning.com/chinese/grammar/Measure_word_%22ge%22#Omitting_the_Number), the default quantity is 1.

In 人的一生中, the 一 is part of the word:

> 一生 (yī​shēng​)  
> [CC-CEDICT](https://www.mdbg.net/chinese/dictionary?wdqb=%E4%B8%80%E7%94%9F): all one's life / throughout one's life

If we delete the 一 from the word 一生, we'd obtain [生](https://www.mdbg.net/chinese/dictionary?wdqb=%E7%94%9F) which is a completely different word. So we can't delete the 一 here.

More generally:

1. There are a bunch of words and idioms containing the character 一 (e.g. 一生, 一起, 一样, 一叶障目): by deleting the 一 from within a word, we'll almost always end up with nonsense.
2. There are a number of grammar structures that also use 一, such as [一……就……](https://resources.allsetlearning.com/chinese/grammar/Events_in_quick_succession_with_%22yi..._jiu...%22). Occasionally it's okay to omit the 一, such as how [一边……一边……](https://resources.allsetlearning.com/chinese/grammar/Simultaneous_tasks_with_%22yibian%22) is sometimes written 边……边……. However, I'd guess for most grammar structures involving 一, it won't be okay to omit the 一.
3. It's often okay to omit the 一 before a [measure word](https://resources.allsetlearning.com/chinese/grammar/Measure_word): 她是一个孩子 = 她是个孩子 but I don't think it's always okay to omit it: I wouldn't start a sentence with a measure word (e.g. I wouldn't write 一匹马在吃草 as just 匹马在吃草), and omitting it in 一个人 might result in confusion with the word [个人](https://www.mdbg.net/chinese/dictionary?wdqb=%E4%B8%AA%E4%BA%BA).


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