Learn Hardcore Chinese: jīntiān shàngwǔ wǒ zài gōngsī kāihuì, xiàwǔ cái yǒukòng. - This morning I had a meeting at the company; I only have free time in the afternoon.

Chinese usually puts time expressions first, before the subject. So 今天上午我在公司开会 is more natural than 我今天上午在公司开会, though both are grammatical and commonly used.

You cannot put the verb before the place like 我在开会公司; that would be wrong. The order time → subject → place → action is a very useful template to remember.

2. What exactly does 在 do here? Does it mean “am”, “at”, or “in the middle of”?

In 我在公司开会, 在 mainly marks location: 在公司 = at the company.

The structure is:

我 + 在公司 + 开会
I + at the company + have a meeting

So in this sentence:

在 is functioning like a preposition “at / in”.
在公司 is a place phrase, telling you where the action happens.

You might also have learned 在 + Verb as a marker of “in the middle of doing something” (like 我在开会 = I’m in a meeting). That use also exists, but here the main job of 在 is to introduce the place: you’re having the meeting at the company.

3. What does 开会 mean exactly? Does it mean I’m holding the meeting or just attending it?

开会 is a verb and means “to have a meeting” / “to be in a meeting.”

It does not by itself say whether you are:

chairing / running the meeting, or
just attending the meeting.

It’s neutral. Context would clarify your role. For example:

我开会呢。 – I’m (in) a meeting now.
我们下午三点开会。 – We’re having a meeting at 3 p.m.

If you want to say specifically that you are hosting it, you could say something like 我主持会议 (I’m chairing the meeting), but 开会 alone doesn’t specify that.

4. How do I know if this means “I had a meeting this morning” or “I will have a meeting this morning”? There’s no tense marker.

Mandarin usually does not mark tense (past / present / future) with verb changes. Instead, it relies on:

time words (like 今天上午), and
context (what time it is, what you’re talking about).

So:

Before noon, this sentence will usually be understood as future or planned:
(今天上午) 我在公司开会，下午才有空。
This morning I’ll be at the company in a meeting, I won’t be free until the afternoon.
After noon, it will usually be taken as past:
This morning I was at the company in a meeting; I’m only free this afternoon.

If you really need to be explicit:

Past: 今天上午我在公司开了会，下午才有空。
Planned/future: 今天上午我要在公司开会，下午才有空。

But in ordinary speech, the original sentence is perfectly natural and people infer tense from context.

5. What does 才 add to the meaning? How is 下午才有空 different from 下午有空?

才 adds the idea of “not until” / “only then”, often with a feeling that the time is later than expected or that it’s the earliest possible time.

下午有空 – I’m free in the afternoon. (a neutral statement of fact)
下午才有空 – I’m *not free until the afternoon / I’ll **only be free in the afternoon.*

So 才 implies:

Before the afternoon, you are not free, and
The afternoon is the first time you’ll be free, possibly later than someone might want.

6. Where does 才 go in the sentence? Could I say 下午有空才?

才 goes before the main verb (or adjective-like predicate) of the clause.

The pattern is:

(Time) + (Subject) + 才 + Verb / Adjective

So correct options include:

下午我才有空。
我下午才有空。
今天上午我在公司开会，下午才有空。

But 下午有空才 is wrong; 才 cannot just be stuck at the end. It must stand before the verb 有 (in 有空).

7. Why is 我 missing in the second part? Why not 下午我才有空?

Chinese often drops the subject if it’s clear from context.

The full form could be:

今天上午我在公司开会，下午我才有空。

This is completely correct and clear.

But since 我 is already established as the subject in the first clause, repeating it in the second is not strictly necessary. So speakers commonly shorten it to:

今天上午我在公司开会，下午才有空。

Both are natural; the shorter version just sounds more fluent and less repetitive.

8. What does 有空 literally mean, and how is it used compared to 有时间?

Literally, 有空 is “to have emptiness / free time”, but idiomatically it means:

to be free / available (time-wise)

Usage:

你明天下午有空吗？
Are you free tomorrow afternoon?
我周末有空。
I’m free on the weekend.

有时间 also means “to have time”, but is a bit more neutral and can focus more on having enough time, not just being free.

最近工作太多，我没有时间运动。
Recently I have too much work; I don’t have time to exercise.

Often you can use either 有空 or 有时间 when asking about availability. 有空 can feel a bit more colloquial / casual in everyday conversation about “Are you free (to do something)?”

9. Can I just use 空 by itself to mean “free”, like 我很空?

Not in normal, natural speech.

我很空 sounds odd or even slightly humorous/weird, like “I’m very empty.”

To say “I’m free / not busy”, more natural options are:

我有空。 – I’m free / I have free time.
我现在很有空。 – I’m really free right now.
我最近比较闲。 – I’m relatively free / not busy recently.
我现在不忙。 – I’m not busy now.

空 does appear in words like 空闲 (kòngxián) and 空着 (empty / left empty), but you don’t normally use 空 alone as an adjective for “free (time)” in this context.

10. Can I change the word order? For example, can I say 我今天上午在公司开会 or 今天上午在公司我开会?

我今天上午在公司开会 – This is correct and natural.
Chinese is flexible about whether time comes before or after the subject, as long as it’s early in the sentence.
今天上午在公司我开会 – This is awkward and not natural for this meaning.
It sounds like you’re emphasizing “it’s me who is having the meeting at the company (not someone else)”, and even then it’s not a typical way to say that.

The safest patterns to memorise are:

今天上午我在公司开会。
我今天上午在公司开会。

But don’t split 在公司 away from the verb in a strange way; keep 在 + place together before the verb phrase.

11. Why is there just a comma between the two parts? Why not use 和 or 所以?

Chinese uses commas much more freely than English to join related clauses, especially when the relationship (sequence, cause, contrast) is obvious.

Here:

今天上午我在公司开会，下午才有空。

The comma connects:

The reason / situation: This morning I’m at the company having a meeting
The result / consequence: So I won’t be free until the afternoon.

You could make the causal link explicit:

今天上午我在公司开会，所以下午才有空。
This morning I’m at the company in a meeting, so I’m only free in the afternoon.

But it’s not necessary; the comma plus 才 already lets listeners infer the causal relationship. Using 和 (and) here would sound odd because the relationship isn’t just “and”, it’s more like “so / therefore”.

12. Could I omit 今天 and still be correct? For example: 上午我在公司开会，下午才有空。

Yes, you can.

上午我在公司开会，下午才有空。

is perfectly grammatical and natural. It just says:

In the morning I’m at the company in a meeting; I won’t be free until the afternoon.

Whether you add 今天 (today) depends on context:

If it’s obvious you’re talking about today, you can drop 今天.
If you want to be explicit that you mean today, keep 今天上午 / 今天下午.

13. What’s the difference between 公司 and 办公室 here? Could I say 在办公室开会 instead?

Yes, you can say 在办公室开会; it’s just a slightly different place:

公司 – the company as an organisation / workplace as a whole.
办公室 – the specific office / office room.

So:

在公司开会 – having the meeting at the company (somewhere on company premises).
在办公室开会 – having the meeting in the office (room).

Both are natural; choose the one that best fits what you want to say about the location.