<p>了  indicates the verb is 'completed' </p>

<p>我们八点上课，老师八点半才到。 would be a correct  sentence</p>

<p><strong>才</strong> in 八点半才 indicated 'reaching 8:30' is a <strong>requirement</strong> for the action 'arrive' to apply, therefore, 到 is not a definitely completed action here. That is why the verb particle 了 that indicates the verb is 'completed' is not applicable when it is following 才 in a sentence.</p>

<p>我们八点上课，老师七点半 就到了 would also be a correct sentence, because 就 indicates 'already' therefore the verb particle 了 that indicates the verb is 'completed' is applicable</p>

<p>Notice:</p>

<p>才 functions differently in different context</p>

<p>Example:</p>

<ol>
<li><p>八点半(才) = (only when it is) 8:30 ; 八点半(才)到 = arrive (only when it is) 8:30</p></li>
<li><p>(才) 八点半 = it is (just) 8:30; (才)八点半就到 = It is (just) 8:30, he already arrived; (才)八点半就到(了) = It is (just) 8:30, he (had) arrived already </p></li>
</ol>

<p>In Example 1. 'when it is 8:30' is a requirement for 'arrive' to happen. Therefore, you cannot add '了' to indicate the verb is completed</p>

CC BY-SA 4.0
2019-07-11T10:17:18.933Z
Thank you very much for taking your time to explain this. I think I understand what you mean, I am just still a little bit confused because I've encountered sentences in which 才 and 了 are used in the same sentence. 
As 米艾莉 has explained in the comment down below, in those cases  才...了 means "just did something". Do you agree? Can you think of more examples?

Thank you again for your kind answer.
Hannah
CC BY-SA 4.0
2019-07-11T10:49:59.367Z
@Hannah See my new notes at the bottom
Tang Ho
CC BY-SA 4.0
2019-07-23T21:31:04.253Z
@TangHo So, 他8:30才到 (he arriveS only at 8:30). 他8:30就到了 (he already arriveD at 8:30). 他才8:30就到 (he ONLY arriveD at 8:30). Is that it?
Enrico Brasil
CC BY-SA 4.0
2019-07-08T19:21:14.473Z
2019-07-11T10:49:25.743Z
2019-07-11T10:49:25.743Z
Tang Ho
<p>Verbs taking 才 do not take 了:</p>
<blockquote>
<p>Note that verbs following 才 should not take 了.</p>
<blockquote>
<p>✘ 我昨天晚上十一点<strong>才</strong>到家<strong>了</strong>。<br />
✘ 她四十岁<strong>才</strong>结婚<strong>了</strong> 。</p>
</blockquote>
<p><sub><a href="https://resources.allsetlearning.com/chinese/grammar/Expressing_lateness_with_%22cai%22" rel="nofollow noreferrer">Expressing lateness with &quot;cai&quot;</a>, Chinese Grammar Wiki</sub></p>
</blockquote>

CC BY-SA 4.0
2019-07-09T01:58:58.717Z
才 and 了 can be used together, but it means something different. For example, "你想去吃饭吗(You wanna go for a meal)?" "我才吃了(I just ate)." Here 才...了 means "just did something".
trisct
CC BY-SA 4.0
2019-07-11T10:13:30.560Z
Thank you very much for your useful explanation. So a sentences such as "我才到了机场" or "我才买了两本书" translate as "I just...". 
Is 才 a shorter version of 刚才 in these sentences?
Hannah
CC BY-SA 4.0
2019-07-08T19:09:40.503Z
2020-01-05T09:26:48.037Z
2020-06-17T09:50:11.587Z
米艾莉
<p>I don't think it's wrong, since it gave correct meaning. </p>

<p>Consider the following sentence, "我们八点上课，老师(一般)七点五十才到". It means the teacher come at 7:50 for most time.</p>

<p>If omitting "了" the original sentence seems means that the teacher will always arrive at 8:30.  However it obviously means that in a particular day, the teacher was late for class. "了" emphasizes that teacher had arrived but was late. When for emphasizing, the verb "到(arrive)" can be a bit stressed.</p>

<p>"了" has a second pronunciation of "liao", which is a more emphasizing tone.</p>

CC BY-SA 4.0
2020-01-10T01:38:04.557Z
Welcome to the site!  From a mostly anonymous forum like this, we don't who is who: so if someone simply says "XYZ is correct" or "ABC is a problem", it's not that useful.  Would it be possible to [edit] in more specific details?  E.g. explain how it's wordy, and give alternative suggestions.  (Also beneficial would be to add links to reliable resources, and related verifiable examples.)
Becky 李蓓
CC BY-SA 4.0
2020-01-07T16:35:02.240Z
2020-01-11T09:29:03.497Z
2020-01-11T09:29:03.497Z
ZFY
<p>What is wrong with this sentence and why? I would like to have a grammatical explanation.
我们八点上课，老师八点半才到了。</p>

<grammar>
What is wrong with this sentence and why? 我们八点上课，老师八点半才到了。
# What is wrong with this sentence and why? 我们八点上课，老师八点半才到了。

(Asked by: username_0 on 2019-07-08)

What is wrong with this sentence and why? I would like to have a grammatical explanation.
我们八点上课，老师八点半才到了。

**Tags:** grammar

---

## 3 answers

### Answer by username_1 on 2019-07-08. Score: 5

了 indicates the verb is 'completed'

我们八点上课，老师八点半才到。 would be a correct sentence

**才** in 八点半才 indicated 'reaching 8:30' is a **requirement** for the action 'arrive' to apply, therefore, 到 is not a definitely completed action here. That is why the verb particle 了 that indicates the verb is 'completed' is not applicable when it is following 才 in a sentence.

我们八点上课，老师七点半 就到了 would also be a correct sentence, because 就 indicates 'already' therefore the verb particle 了 that indicates the verb is 'completed' is applicable

Notice:

才 functions differently in different context

Example:

1. 八点半(才) = (only when it is) 8:30 ; 八点半(才)到 = arrive (only when it is) 8:30
2. (才) 八点半 = it is (just) 8:30; (才)八点半就到 = It is (just) 8:30, he already arrived; (才)八点半就到(了) = It is (just) 8:30, he (had) arrived already

In Example 1. 'when it is 8:30' is a requirement for 'arrive' to happen. Therefore, you cannot add '了' to indicate the verb is completed

> **Comments:**
> **username_0**: Thank you very much for taking your time to explain this. I think I understand what you mean, I am just still a little bit confused because I've encountered sentences in which 才 and 了 are used in the same sentence.  As 米艾莉 has explained in the comment down below, in those cases  才...了 means "just did something". Do you agree? Can you think of more examples?  Thank you again for your kind answer.  
> **username_1**: @Hannah See my new notes at the bottom  
> **username_2**: @TangHo So, 他8:30才到 (he arriveS only at 8:30). 他8:30就到了 (he already arriveD at 8:30). 他才8:30就到 (he ONLY arriveD at 8:30). Is that it?  

---

### Answer by username_3 on 2019-07-08. Score: 2

Verbs taking 才 do not take 了:

> Note that verbs following 才 should not take 了.
>
> > ✘ 我昨天晚上十一点**才**到家**了**。  
> > ✘ 她四十岁**才**结婚**了** 。
>
> [Expressing lateness with "cai"](https://resources.allsetlearning.com/chinese/grammar/Expressing_lateness_with_%22cai%22), Chinese Grammar Wiki

> **Comments:**
> **username_4**: 才 and 了 can be used together, but it means something different. For example, "你想去吃饭吗(You wanna go for a meal)?" "我才吃了(I just ate)." Here 才...了 means "just did something".  
> **username_0**: Thank you very much for your useful explanation. So a sentences such as "我才到了机场" or "我才买了两本书" translate as "I just...".  Is 才 a shorter version of 刚才 in these sentences?  

---

### Answer by username_5 on 2020-01-07. Score: 0

I don't think it's wrong, since it gave correct meaning.

Consider the following sentence, "我们八点上课，老师(一般)七点五十才到". It means the teacher come at 7:50 for most time.

If omitting "了" the original sentence seems means that the teacher will always arrive at 8:30. However it obviously means that in a particular day, the teacher was late for class. "了" emphasizes that teacher had arrived but was late. When for emphasizing, the verb "到(arrive)" can be a bit stressed.

"了" has a second pronunciation of "liao", which is a more emphasizing tone.

> **Comments:**
> **username_6**: Welcome to the site!  From a mostly anonymous forum like this, we don't who is who: so if someone simply says "XYZ is correct" or "ABC is a problem", it's not that useful.  Would it be possible to [edit] in more specific details?  E.g. explain how it's wordy, and give alternative suggestions.  (Also beneficial would be to add links to reliable resources, and related verifiable examples.)  

---

