xìngkuī wǒmen yùdìng le bāoxiāng, bùrán jīnwǎn méiyǒu fángjiān.

幸亏 means luckily, fortunately, or it’s a good thing that.

It usually suggests that something bad was avoided. In this sentence, the bad outcome is in the second half: 不然今晚没有房间. So the feeling is:

Luckily, we reserved a private room; otherwise there wouldn’t be any rooms tonight.

They make a very common pattern in Chinese:

幸亏 + lucky fact/action, 不然 + bad result

So here:

• 幸亏我们预订了包厢 = Luckily, we reserved a private room
• 不然今晚没有房间 = Otherwise, there would be no rooms tonight

This pairing is very natural because 幸亏 introduces what saved the situation, and 不然 introduces what would have happened without it.

The 了 here marks the action as completed.

So 预订了包厢 means reserved a private room or have reserved a private room. The important idea is that the reservation had already been made, and that completed action is why the problem was avoided.

It is not just a simple past tense marker like in English. It often shows that an action is completed and relevant to the current situation.

You could, but it would not fit this sentence as well.

In this context, the speaker is talking about a completed action that protected them from a problem. So 预订了 is the natural choice.

• 我们预订了包厢 = We reserved a private room
• 我们预订包厢 = We reserve private rooms / we are reserving a private room / a more unanchored statement depending on context

Because 幸亏 refers to something that already happened, 了 is very helpful here.

Both can mean to book or to reserve.

The difference is mainly one of style and nuance:

• 预订 = more formal, often emphasizes booking in advance
• 订 = shorter, more common in everyday speech

So both of these work:

• 我们预订了包厢
• 我们订了包厢

In daily conversation, 订了包厢 is very common and natural.

包厢 usually means a private room or private compartment, especially in places like:

• restaurants
• KTVs
• tea houses

房间 is a general word for room.

So in this sentence:

• 包厢 = the specific kind of room they reserved
• 房间 = rooms in general

If the speaker wanted to emphasize that specifically no private rooms were left, they might say:

不然今晚没有包厢了。

But 没有房间 is broader and still works.

Because 有 is normally negated with 没 or 没有, not with 不.

So:

• 有房间 = there are rooms
• 没有房间 = there are no rooms

不有 is not standard Mandarin.

This is a basic pattern you should remember:

• 有 → 没有
• 是 → 不是
• 想 → 不想

It can be said without 了, but many native speakers would very naturally say:

不然今晚没有房间了。

The final 了 would add the feeling of now there are none left or the situation has changed.

So the difference is roughly:

• 没有房间 = there are no rooms
• 没有房间了 = there are no rooms left now

Both are understandable, but 没有房间了 often sounds more natural in this kind of situation.

In Chinese, time words often come before the verb or predicate.

So:

• 今晚没有房间 = Tonight there are no rooms
• literally: tonight + not have + rooms

This follows a very common Chinese word order:

subject + time + verb/predicate + object

For example:

• 我明天上班。 = I work tomorrow.
• 我们今天很忙。 = We are busy today.
• 他晚上不回家。 = He isn’t going home tonight.

Yes.

This sentence has an implied conditional meaning. Even without 如果, the pattern 幸亏... 不然... clearly expresses:

• a real fact: we reserved the private room
• an unreal or avoided result: otherwise there would be no rooms tonight

So the logic is basically:

Because we did X, bad result Y did not happen. If we had not done X, Y would have happened.

This kind of conditional meaning is very common in Chinese and often does not need 如果.

Sometimes yes, if the context is already clear.

For example, in conversation, someone might simply say:

幸亏预订了包厢，不然今晚没有房间。

That is perfectly possible if everyone already knows who made the reservation.

But keeping 我们 makes the sentence clearer and more complete, which is often helpful for learners.