Lan tham gia rồi đi dạo.

Tham gia means to participate, to take part, or to join in.

It often takes an object, for example:

• tham gia cuộc họp = participate in the meeting
• tham gia câu lạc bộ = join the club

In Lan tham gia rồi đi dạo, the thing Lan participated in is not stated, so it is understood from context.

Here, rồi links two actions and shows sequence. It means something like and then, after that, or once that was done.

So the structure is:

Lan + tham gia + rồi + đi dạo

This tells you that the second action happened after the first one.

Not exactly.

Rồi can mean different things depending on position and context:

• sentence-final rồi often means already
  
  • Tôi ăn rồi. = I already ate / I’ve eaten.
• between two verbs, as in this sentence, it usually means then / after that

So in Lan tham gia rồi đi dạo, rồi is mainly marking order, not just saying already.

Vietnamese often does not need a separate word like English and when two actions are connected clearly.

In this sentence, rồi already gives the idea of and then, so adding và is unnecessary.

Compare:

• Lan tham gia rồi đi dạo. = Lan participated and then went for a walk.
• Lan tham gia và đi dạo. = Lan participated and walked.

The version with rồi sounds more sequential. The version with và just lists two actions and does not emphasize order as strongly.

Because the subject is still the same.

Vietnamese often omits a repeated subject when it is obvious from context. So once Lan is introduced, the second verb phrase is understood to have the same subject.

That means:

Lan tham gia rồi đi dạo

naturally means that Lan did both actions.

Yes. Đi dạo is a common verb phrase meaning to go for a walk or to take a stroll.

Literally:

• đi = go
• dạo = stroll / wander

But together, they function as a single expression. You should learn đi dạo as a set phrase.

Vietnamese does not mark tense the same way English does.

This sentence has no special past-tense verb form. Instead, time comes from context. In this sentence, rồi suggests that one action happened before the next one, so an English past translation is often natural. But depending on context, it could also be part of a story, a routine description, or even a plan.

So the sentence itself is not strictly marked as past in the way English verbs are.

Yes, it is grammatically fine, but it depends on context.

Since tham gia usually means participate in something, a listener may naturally wonder: participate in what? If the event is already known from the conversation, leaving it out is normal. If there is no context, the sentence can feel a little incomplete.

So this is natural when the missing information is already understood.

Usually, no, not if you want to clearly show two separate actions in sequence.

Without rồi, Lan tham gia đi dạo sounds odd and could be confusing. It may no longer clearly mean:

• first, participate
• then, go for a walk

Using rồi helps separate the two actions and makes the sequence clear.