Chúng tôi phải đợi ở đó vì cửa đã đóng.

A simple breakdown is:

• Chúng tôi = subject
• phải = modal verb, have to / must
• đợi = main verb, wait
• ở đó = location, there
• vì cửa đã đóng = reason clause, because the door was closed / had already closed

So the pattern is:

subject + modal + verb + location + reason

That is a very common Vietnamese sentence pattern.

Chúng tôi means we, but it is exclusive: it does not include the listener.

So:

• chúng tôi = we, not including you
• chúng ta = we, including you

This is something English does not normally mark, so it is very common for learners to ask about it.

Also, chúng tôi sounds fairly neutral or somewhat formal. In casual speech, people may also say things like tụi tôi or bọn tôi, depending on region and style.

Here phải means must / have to.

So phải đợi means have to wait.

Because the sentence describes a past situation, English often translates it as had to wait, but phải itself does not change form. Vietnamese does not conjugate verbs the way English does.

Also, in other contexts phải can have different meanings, such as correct/right, but in this sentence it is clearly the modal have to.

Because Vietnamese verbs do not change form for tense the way English verbs do.

The verb đợi stays đợi whether the action is present, past, or future. Time is usually understood from:

• context
• time words like hôm qua = yesterday
• markers like đã, đang, sẽ

In this sentence, the situation is understood as past because of the context and because cửa đã đóng shows that the closing had already happened.

If you want to make the past more explicit, you could say:

• Chúng tôi đã phải đợi ở đó...

That more clearly gives the idea of we had to wait there.

Usually, yes.

Both đợi and chờ can mean to wait, and in many everyday sentences they are interchangeable.

So you could also say:

• Chúng tôi phải chờ ở đó vì cửa đã đóng.

The meaning is basically the same.

There can be small differences in style, habit, or regional preference, but for most learners it is safe to think of them as near-synonyms in a sentence like this.

Because ở marks location: at / in.

• đó = there / that place
• ở đó = at there / there

After đợi, if you want to say where someone waits, you normally use a location phrase with ở:

• đợi ở đây = wait here
• đợi ở đó = wait there
• đợi ở nhà = wait at home

Saying đợi đó would not sound natural in this meaning.

Vì means because.

In this sentence:

• vì cửa đã đóng = because the door was closed / had already closed

Yes, the reason clause can also come first:

• Vì cửa đã đóng, chúng tôi phải đợi ở đó.

That is also natural. The difference is mostly one of emphasis and flow:

• Chúng tôi phải đợi ở đó vì... puts the main action first
• Vì... , chúng tôi phải đợi ở đó puts the reason first

Vietnamese does not have articles like a and the.

So a noun like cửa can often stand by itself when the context makes it clear which door, gate, or entrance is meant.

Depending on context, cửa can mean:

• door
• gate
• entrance
• shop/business in some other contexts

In this sentence, it most likely means door or gate, depending on the situation.

You may also hear cái cửa, where cái is a classifier, but it is not required here. Bare cửa is completely normal.

Đã is an aspect/time marker placed before the word it modifies.

Here it shows that the closing happened before the relevant point in time, or that the door was already in the closed state.

So cửa đã đóng can be understood as:

• the door closed
• the door had closed
• the door was already closed

Exactly which English version is best depends on context.

A very important point: đã is often translated as a past marker, but it is not exactly the same as an English past tense ending. It marks completedness or prior occurrence rather than changing the verb itself.

It can function like either, which is very common in Vietnamese.

Đóng can mean:

• to close / to shut
  or
• closed / shut

In cửa đã đóng, it describes the state of the door after closing. English would often use was closed, but Vietnamese does not need a separate word meaning was here.

That is why the sentence can look short to English speakers:

• cửa đã đóng

but it is perfectly complete in Vietnamese.

Yes, you often can.

• cửa đã đóng
• cửa đóng rồi

Both can mean that the door is already closed.

A rough difference is:

• đã đóng sounds a bit more neutral or narrative
• đóng rồi is very common in speech and often feels more immediate, like it’s closed already

So this version is also natural:

• Chúng tôi phải đợi ở đó vì cửa đóng rồi.

It is especially common in everyday spoken Vietnamese.