了 vs 完 (le vs wán): completed vs finish
了 (le) is a perfective aspect marker indicating that an action is viewed as complete or a new situation has arisen. 完 (wán) is a result complement meaning 'to finish' an action, emphasizing that it has reached its endpoint. They can combine (e.g., 吃完了) to highlight both completion and finishing, but each has distinct uses. 핵심 차이: 了 marks aspect, 完 marks result.
了 (le) marks the perfective aspect, treating an event as a single completed whole or a change of state. 完 (wán) is a result complement that indicates an action has reached its natural end or 'finish'. While both relate to completion, 了 is grammatical (aspect) and 完 is lexical (result). They often appear together (V+完+了) to reinforce that the action finished and the situation is complete, but each can appear independently: 了 without 完 merely marks the action as complete (e.g., 我吃了饭 'I ate'), while 完 without 了 emphasizes the result of finishing, especially in sequential narratives (e.g., 我做完作业就去玩 'After finishing homework, I'll go play').
When to use each
Use 了 to indicate that an action is considered complete as a whole, often in past events (e.g., 我看了一本书 'I read a book') or to mark a change of state (e.g., 花红了 'The flower has become red'). It can also express imminent future in some contexts (e.g., 快下雨了 'It's about to rain'). 了 is mandatory in sentences where the perfective meaning is required, especially in past-time contexts.
了 does not specify whether an action reached its endpoint; it only marks the event as bounded. For example, 我写了两封信 means 'I wrote two letters', but doesn't say if I finished them or not; it simply reports the completion of the writing action with a specified quantity.
Use 完 as a result complement after a verb to emphasize that the action has reached its end or is fully carried out. Common verbs include 吃完 (finish eating), 做完 (finish doing), 看完 (finish reading/watching). It can appear alone (e.g., 我做完了 'I'm done') or with 了. In sequential past narratives, 完 can appear without 了 to show that one finished action precedes another (e.g., 我吃完饭就走了 'I finished eating and then left').
完 without 了 in affirmative sentences often implies sequence or future intent, not incompleteness (e.g., 我做完作业才睡觉 'I'll sleep only after finishing homework'). Negation uses 没 (e.g., 我没做完 'I haven't finished'), where 完 still indicates result; the lack of 了 is due to negation, not an 'unfinished' meaning of 完 itself.
At a glance
| 了 | 完 | |
|---|---|---|
| Grammatical function | Perfective aspect marker (grammatical) | Result complement (lexical) |
| Core meaning | Action viewed as complete or change of state | Action reached its endpoint/finish |
| Can appear without the other? | Yes; marks completion without specifying endpoint | Yes; in sequential contexts or with negation |
| Combined usage | N/A | V+完+了 emphasizes both result and perfective aspect |
| Negation | 没/没有 + V (+ 了 is dropped) | 没 + V + 完 (了 dropped due to negation) |
| Implies the action actually finished? | Not necessarily; e.g., 我写了那封信 but might not have sent it | Yes; the action is carried out to its natural end |
Examples
- 了我吃了午饭。Wǒ chīle wǔfàn.I ate lunch.了 marks lunch-eating as a completed event; does not specify if I finished all the food.
- 完我吃完饭了。Wǒ chī wán fàn le.I have finished eating (my meal).完 emphasizes the action of eating reached its end; 了 adds perfective aspect.
- 完我吃完饭就走了。Wǒ chī wán fàn jiù zǒule.I finished eating and left.完 without 了 in the first clause shows sequence; the second clause uses 了 for past completion.
- 了我看了三本书。Wǒ kànle sān běn shū.I read three books.了 marks the event of reading three books as complete; does not specify if each book was fully read.
- 完我看完这本书了。Wǒ kàn wán zhè běn shū le.I have finished reading this book.完 indicates I read the entire book; 了 confirms the perfective state.
- 完他写完信才睡觉。Tā xiě wán xìn cái shuìjiào.He only goes to sleep after finishing writing the letter.完 without 了 in a future/habitual context; sequence marker 才 ties the result to the next action.
Common mistakes
- Using 了 instead of 完 when you want to emphasize that an action was fully finished (e.g., saying '我吃了一本书' for 'I finished reading a book' should be '我看完了一本书' or '我读完了一本书').
- Using 完 instead of 了 to mark simple past completion without implying 'finish' (e.g., '我写完了一本书' when you mean 'I wrote a book' but not necessarily finished — better: '我写了一本书').
- Omitting 了 after 完 in all past-tense sentences: 完 can stand without 了 in sequential narratives (e.g., '我做完作业就睡觉' is correct; '我做完作业了睡觉' is unnatural).
- Thinking 完 always needs 了 to express completion: in affirmative sequential contexts, 完 alone carries the result meaning (e.g., '我买完东西回家' is fine).
- Using 了 after 完 to mean 'already' when the focus is on the sequence: '了我吃完饭就' is wrong; use 完 alone in the first clause.
FAQ
- When do I use 了 vs 完?
- Use 了 when you want to mark an event as completed or a new situation (perfective aspect). Use 完 when you specifically want to say the action has been finished to its end. If you just want to say 'I ate' without emphasis on finishing, use 我吃了. If you want to say 'I finished eating,' use 我吃完了.
- Can I use 完 without 了?
- Yes. In sequential past narratives (e.g., 我做完作业就回家了 'After finishing homework, I went home'), 完 alone indicates the result of finishing, and 了 is optional in the first clause. Also in imperative or future contexts (e.g., 吃完再走 'Eat before you go').
- Do I need 了 after 完 in all completed actions?
- No. If the sentence is in a past narrative and the focus is on the sequence of events, 完 alone is sufficient. However, if you want to emphasize that the finishing is a new state or relevant to the present, add 了 (e.g., 我吃完了, so now I'm full).
- What is the difference between 没吃完 and 没吃了?
- 没吃完 means 'haven't finished eating' – the action is incomplete in terms of reaching its end. 没吃了 (rare and usually incorrect without a classifier) would mean 'did not eat (something)' but 没吃了 is not standard; the correct negation for perfective is 没吃 (I didn't eat). 没 + V + 完 negates the result of finishing; 没 + V negates the action itself.