How It Works

In Vietnamese, Verb + mất is a highly frequent resultative construction. While mất literally means 'to lose', 'to pass away', or 'to take/cost (time, money, effort)', here it functions as an aspectual marker indicating that an action has reached—or might reach—a state of irreversibility, disappearance, or loss.

1. Structure and Word Order
Because Vietnamese is an isolating language, there are no morphological changes to the verb. The particle mất can attach directly to the right of the main verb (or an adjective functioning as a predicate), or it can sit after the object. Both Verb + mất + Object and Verb + Object + mất are common. It is frequently paired with the final particle rồi to emphasize completion.

Tôi quên mất mật khẩu. / Tôi quên mật khẩu mất rồi. (I completely forgot the password.)

2. Speaker Attitude and Nuance
This pattern is not just about completion; it encodes the speaker's attitude. It typically carries a negative connotation, expressing regret, dismay, or a feeling that the outcome is unfortunate and out of the speaker's control. For general neutral completion, you would use the perfective particle rồi (e.g., Người ta mua rồi vs. Người ta mua mất rồi). The word Verb + xong is specifically for finishing intentional tasks, not involuntary actions.

3. Future and Preventative Anxiety
A crucial usage of mất is for future or hypothetical actions, expressing anxiety that an undesirable state might be reached. It is frequently used with verbs of fear (like lo or sợ) or the preventative conjunction kẻo (or else / lest) to warn about unlucky things that might happen.

Nhanh lên kẻo trễ mất! (Hurry up or else we'll be late!)
Tôi sợ quên mất. (I'm afraid I will forget.)

4. Abstract vs. Physical Loss and Involuntary Actions
A common misconception is that mất requires a physical object to be lost. In reality, it is heavily used with abstract concepts (like memory in quên mất) or missed opportunities. Furthermore, it is frequently used with positive verbs to frame an action as involuntary or an 'accident' (e.g., lỡ yêu mất rồi = accidentally fell in love; thích mất rồi = caught feelings), reinforcing the idea that the action is out of the speaker's control. Note that mất by itself does not intensify adjectives; it only acts as an intensifier when locked into specific, fixed idiomatic constructions (e.g., mệt chết mất = tired to death; ngon chết mất = so delicious I could die; đẹp quá mất thôi = just too beautiful).

5. Verbs of Motion and Disappearance
When paired with verbs of motion (such as đi, chạy, or bay), mất indicates physical disappearance, translating to 'away' or 'gone'. This bridges the gap between the literal meaning of 'to lose' and the abstract aspectual marker of disappearance.

Con chim bay mất rồi. (The bird flew away.)
Anh ấy đi mất rồi. (He is gone.)

6. Contrasting with Similar Patterns

vs. hết: Verb + hết focuses on the depletion of quantity (zero remaining). Mất focuses on the regret or irreversibility of the action.
vs. được: As a resultative complement, được is the semantic opposite of mất, marking a positive gain or successful attainment (e.g., lấy được = successfully obtained vs. lấy mất = taken away).

7. Important Distinctions

Losing a physical object: To say you lost a physical object through your own mistake, use the causative làm mất (to make lost). For example, Tôi làm mất chìa khóa (I lost my keys). Tôi mất chìa khóa is also natural and just says the keys are gone, without stressing who caused it.
Consuming time or effort: Mất can also act as a main verb meaning 'to take' or 'to consume' time/effort (e.g., Sửa xe mất một tiếng = Fixing the car takes an hour). Do not confuse this with the resultative pattern.

Examples (6)

Tôi hoàn toàn quên mất việc này rồi!
I completely forgot about this!
Word by Word: I completely forget lose affair this already!
Notice how 'mất' sits directly after the verb 'quên' and before the object 'việc này', showing that the memory is irreversibly gone.
Ai ăn mất cái bánh của tôi rồi?
Who ate up my cake?
Word by Word: Who eat lose classifier cake belonging to me already?
Implies dismay that the cake is gone and the speaker is deprived of it.
Cái máy tính hỏng mất rồi.
The computer is completely broken.
Word by Word: Classifier computer broken lose already.
Used with an adjective/stative verb (hỏng) to express an unfortunate, irreversible negative state.
Trời nóng chết mất!
It's so hot I could die!
Word by Word: Sky hot die lose!
Demonstrates that 'mất' doesn't require a literal physical loss; here it exaggerates a negative, uncontrollable state.
Kẻ trộm đã lấy mất chiếc xe đạp.
The thief took away the bicycle.
Word by Word: Thief already take lose classifier bicycle.
Shows a literal loss where the action (lấy) results in the object being taken away from the owner.
Con chim bay mất rồi.
The bird flew away.
Word by Word: Classifier bird fly lose already.
When paired with a verb of motion like 'bay' (to fly), 'mất' indicates that the subject has physically disappeared or gone away.

Common Mistakes

Using 'mất' for positive attainment or receiving something good.
Tôi tìm mất chìa khóa.
Tôi tìm được chìa khóa.
When you successfully attain or find something, use 'được'. 'Mất' implies losing something or an unfortunate result.
Confusing 'mất' (irreversible loss/regret) with 'hết' (depletion of quantity).
Tôi đã đọc mất cuốn sách này.
Tôi đã đọc hết cuốn sách này.
Use 'hết' when you mean 'finished completely' or 'zero quantity remaining'. Use 'mất' only when the completion involves regret, loss, or an unfortunate outcome.
Using 'mất' for neutral completion instead of 'xong' or 'rồi'.
Tôi làm bài tập mất.
Tôi làm bài tập xong rồi.
'Mất' injects a tone of regret or loss. For simply stating that an action is completed neutrally, use 'rồi'. Use 'xong' specifically when you have finished an intentional task or process.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

Verb + mấtLevel 4And It Is Gone

Learn This First

To understand 'Verb + mất', you need to be familiar with how Vietnamese uses resultative verbs to indicate that an action has reached a specific conclusion. It specifically marks a result that involves loss, disappearance, or regret. Familiarity with other resultative markers like 'đi' and the adverse passive 'bị' helps contextualize the negative nuance of this pattern.

Words in This Pattern

mất