Cậu đã dậy.

Here, cậu means you, but it is not a universal word for you.

It is usually used:

• with someone around your age
• with someone younger
• in a fairly casual or familiar relationship

Compared with bạn, cậu often feels more personal or relationship-based. Bạn is usually safer if you want a more neutral you.

So cậu works only when the social relationship fits.

Yes. Vietnamese words often depend heavily on context, and cậu is a good example.

Besides being a pronoun meaning you, cậu can also mean:

• maternal uncle
• a form of address in some family or regional patterns

In Cậu đã dậy, the meaning is clearly the pronoun you, not the family noun.

Đã is an aspect/time marker. In a sentence like this, it usually shows that the action is viewed as having already happened or been completed.

So it often corresponds to ideas like:

• already
• English past tense
• English present perfect

That does not mean đã is a one-to-one translation of English did or have. Vietnamese does not mark tense the same way English does. Đã helps place the action in a completed or past-like frame.

Not exactly.

A better way to think of đã is that it often marks an action as realized, completed, or already occurring by some reference point. In many everyday sentences, that ends up looking like past tense in English, but Vietnamese is not built around tense in the same way.

So in this sentence, đã suggests something like:

• the person is already up
• the getting-up happened before now or before some other point in the conversation

Context decides the best English translation.

Dậy literally has the idea of getting up / rising. Depending on context, English may translate it as:

• wake up
• get up
• be up

In real usage, the boundary is not always as sharp as in English. If you want to be more explicit about wake up, Vietnamese often uses thức dậy.

So:

• dậy = get up / be up / wake up depending on context
• thức dậy = more clearly wake up

Because Vietnamese does not build sentences with the same kind of auxiliary system as English.

English says things like:

• You have gotten up
• You woke up
• You are up

Vietnamese often uses:

• a pronoun
• an aspect marker such as đã
• the main verb

So Cậu đã dậy is completely normal even though there is no separate word corresponding to English have.

The basic pattern here is:

subject + aspect marker + verb

So:

• cậu = subject
• đã = aspect/time marker
• dậy = verb

This is very common in Vietnamese. English often changes the verb itself or adds auxiliaries, but Vietnamese frequently keeps the main verb simple and adds small words before it.

Both are natural, but they feel a little different.

Cậu đã dậy:

• focuses on the action as already completed
• can sound slightly more neutral or written

Cậu dậy rồi:

• is very common in speech
• strongly suggests a current resulting state: the person is up now

You may also hear Cậu đã dậy rồi, which adds extra emphasis that the action has indeed already happened.

So yes, Cậu đã dậy is fine, but rồi is often very common in everyday spoken Vietnamese.

Yes. In Vietnamese, đ and d are different letters and usually different sounds.

• đ in đã is a true d sound
• d in dậy is different:
  • in Northern Vietnamese, it sounds roughly like English z
  • in Southern Vietnamese, it often sounds roughly like English y

This is why learners often need to pay close attention to Vietnamese spelling: two letters that look similar can represent different sounds.

Very commonly:

• Cậu dậy chưa? = Are you up yet? / Have you gotten up yet?
• Cậu đã dậy chưa? = also Have you gotten up yet?
• Cậu chưa dậy. = You haven’t gotten up yet.

A useful pattern is:

• đã ... chưa? for have/has ... yet?
• chưa by itself for not yet

So this sentence connects naturally to one of the most common Vietnamese patterns learners meet early on.