Quick Answer
Both Đã and Rồi are used to indicate that an action has been completed. Generally, Đã marks an action as completed in the past, similar to the simple past tense in English, focusing on the event's occurrence. On the other hand, Rồi often emphasizes the completion of an action, implying a resultant state, a sequence of events, or the nuance of 'already'.
Comparison Table
| Feature | Đã | Rồi |
|---|---|---|
| Primary Function | Marks simple past completion, action occurred. | Marks completion, often with nuance of "already," sequential, or resulting state. |
| Position | Before the verb/verb phrase. | After the verb/verb phrase. |
| Focus | On the action's occurrence in the past. | On the state of completion or its consequence. |
| Example |
Tôi đã ăn cơm. I ate rice. |
Tôi ăn cơm rồi. I've eaten rice (already). |
Detailed Explanation
Now, we'll look closely at these two common words that mark completed actions in Vietnamese.
When to use Đã
Đã (Hán-Việt: 已 - yǐ, meaning 'already' or 'past') functions much like the simple past tense in English. It indicates that an action happened at a specific or implied point in the past. When you use đã, you're stating a historical fact about an action. It's often used with specific time markers like 'hôm qua' (yesterday), 'tuần trước' (last week), 'năm ngoái' (last year).
Think of đã as simply asserting that an event took place. The focus is on the event's occurrence, not necessarily its current relevance or a subsequent action.
When to use Rồi
Rồi is more versatile and often carries the nuance of "already," "then," or "after that." It emphasizes the completion of an action and its resulting state or a subsequent event. When you use rồi, you're often highlighting that something is finished, and this completion might have implications for the present or the next step.
For example, saying "Tôi ăn cơm rồi" doesn't just mean "I ate rice," but rather "I've already eaten rice," often implying "so I'm full now," or "I'm ready for the next thing." Rồi is crucial in questions like "Bạn ăn cơm chưa?" (Have you eaten yet?) where the expected affirmative answer is "Tôi ăn rồi."
In Southern Vietnamese, rồi is also very commonly used to mark simple completion, sometimes even more frequently than đã in conversational contexts, making it a very natural and widespread marker for 'finished' or 'already done'.
Example Pairs
Tôi đã xem bộ phim đó.
I watched that movie.
Tôi xem bộ phim đó rồi.
I've watched that movie (already).
Anh ấy đã đi chợ.
He went to the market.
Anh ấy đi chợ rồi.
He has gone to the market (already).
Cô ấy đã đọc xong sách.
She finished reading the book.
Cô ấy đọc xong sách rồi.
She has finished reading the book (already).
Hôm qua trời đã mưa.
It rained yesterday.
Trời mưa rồi.
It has rained (and stopped now).
Chúng tôi đã mua nhà mới.
We bought a new house.
Chúng tôi mua nhà mới rồi.
We've bought a new house (already).
Bạn đã làm bài tập chưa?
Did you do your homework yet?
Bạn làm bài tập xong chưa? Tôi làm rồi!
Have you finished your homework yet? I finished it (already)!
Tôi đã gặp anh ấy.
I met him.
Tôi gặp anh ấy rồi.
I've met him (already).
Bác sĩ đã kiểm tra cho tôi.
The doctor examined me.
Bác sĩ kiểm tra cho tôi rồi.
The doctor has examined me (already).
Common Patterns
Verb + xong rồi: This is a very common and strong way to express "finished doing X." It clearly indicates completion and is often used in response to questions about progress.
Bạn làm xong bài tập chưa? Tôi làm xong rồi!
Have you finished your homework yet? I've finished it already!
Chưa... rồi: This is the standard way to ask "Have you done X yet?" and answer "Yes, I have (already)."
Bạn ăn cơm chưa? Tôi ăn rồi.
Have you eaten yet? I've eaten already.
Đã từng + Verb: This pattern is used to express "have ever done" or "used to do" something, emphasizing past experience.
Tôi đã từng đi Đà Lạt.
I have been to Da Lat before.
Common Mistakes
Mistake 1 — Using Đã in a Chưa...Rồi context
Learners often try to answer a 'chưa' question with 'đã' because it signifies the past. However, 'rồi' is the natural and expected response here.
❌ Bạn ăn cơm chưa? Tôi đã ăn.
✅ Bạn ăn cơm chưa? Tôi ăn rồi.
While 'Tôi đã ăn' is grammatically correct for "I ate," it doesn't carry the "already" nuance needed to answer a "yet" question naturally. 'Tôi ăn rồi' clearly conveys "I've eaten already."
Mistake 2 — Incorrect position of Rồi
As 'đã' comes before the verb, learners sometimes mistakenly place 'rồi' there too.
❌ Tôi rồi đi học.
✅ Tôi đi học rồi.
'Rồi' acts as a particle or adverb modifying the completion of the action, so it generally follows the verb or verb phrase it completes.