If I understood correctly, both 完 and 了 can be used to indicate a completed action, so what is the difference in use? How do we properly use 完 in a sentence? Which contexts would be valid?

  • Sometimes we use both: 写完了报告 (finished the report)
    – fefe
    Commented Dec 26, 2011 at 15:52
  • @fefe: Oh my..I'm up for a treat then! >_< Commented Dec 26, 2011 at 16:01

6 Answers 6


You can use 完 and 了 together or separately.

  • 了 is usually used to indicate the completion of an action. E.g. 你买了好多东西 (You purchased a lot of stuff). See the question "Tense and use of 了" to learn more.
  • 完 is used to indicate the action of completing/finishing something. E.g. "說話沒完的人" (a motormouth, someone who talks to no end). Usually it's verb + 完.

完了 can have 3 different meanings/uses.

  1. Verb + 完了 can indicate that the (verb) action has come to an end.
  2. Noun + 完了 indicate the feeling of despair or the end of something . E.g., 哎呀,我完了! (On no, I'm finished/done for!) or 那個車完了(That car is finished/done for!).
  3. 完了 by itself (usually at the beginning of a sentence) is usually an exclamation of despair. E.g., 完了, 车没油了!回不了家了! (We're/I'm done [for], the car's out of gas. We/I can't go [back] home [now]).

没完 can be used to describe things left undone, or something never-ending/eternal. E.g., 活儿还没完 (Work is not done/finished yet) or "說話沒完的人" (a motormouth, someone who talks to no end).

  • 完了 at the beginning of a sentence nearly always is an exclamation of despair. "完了, 敵人被打敗了!" sounds weird, it sounds like that the speaker don't want the enemy to be defeated.
    – fefe
    Commented Dec 26, 2011 at 17:28
  • "没完" does not have the meaning of never-ending. At least I cannot think of a situation it is used in this way. Another phrase means never-ending is "没完没了"
    – fefe
    Commented Dec 26, 2011 at 17:35
  • @fefe I guess I was thinking more along the lines of "說話沒完的人" (a motormouth, someone who talks to no end). As for "完了" I guess I was thinking about more in the context of exclamation or statement such as "完了, 完了, 彻底完了" (It's done/finished, it's done/finished, it's completely done/finished).
    – Krazer
    Commented Dec 26, 2011 at 18:35
  • "完了, 完了, 彻底完了" is an exclamation which implies there is no way to recover from the current (bad) situation. It can have the translation you give, only in certain contexts. "說話沒完的人" is a good example for "没完" (never-ending) , but "一個没完的梦" is not.
    – fefe
    Commented Dec 27, 2011 at 1:50
  • @fefe Fair enough. I'll make the changes.
    – Krazer
    Commented Dec 27, 2011 at 2:32

The other answers give some good examples, so I'll try to provide an answer from a grammatical perspective.

完 can be used as a resultative complement meaning "to finish doing something". You put it after a verb to mean that you finished doing that verb. 「吃完」 means "finish eating".

了 has many different uses, but the one that I first learned was as a past tense marker. 「吃了」 means "ate".

Now, to talk about something that you finished doing in the past, you combine the two. 「我吃完了」 means, "I finished eating."

There's a ton more detail to learn with these two words. I suggest you look at the Chinese grammar wiki complements page, the completion with 了 page, and maybe the many uses of 了 page. I expect most beginner or early intermediate textbooks will cover these topics as well.


I would translate 完 as "complete," and 了 as "done." 完了 would then be a very emphatic "completely done."


All answers miss an important point: the two words are total two different stuff at all! 完 is a verb while 了 is an auxiliary word.

完 in case of this question is used as a secondary part of a compound verb, it denotes the result of the dominated verb. Such kind of compound verbs are called Resultative Compound Verbs. In most situations, say 写完了报告, 了 is used with the whole compound verb instead of just 完. They are not connected as they seem!


so instead of saying, 没看完了 ... one would say 沒有看完 or沒有吃完 for eating...


没 and 完 can be used together to indicate an action that has yet to be completed in this pattern 没 + V + 完 for example:

没看完 or 没吃完

To mean I haven't finished watching/reading it or I haven't finished eating (it)

You can also combine the two in this case it would be:

没看完了 or 没吃完了

To mean the same as above.

However the following:

没看了 or 没吃了

This means I haven't seen/read (it) or I haven't eaten (it)


这本书我还没看了 or 他的冰淇淋还么吃了

I (still) haven't read this book or He/she hasn't eaten their ice-cream.

  • This is not what the OP is asking, I think. All the "了" should be changed into "呢" in your examples. "了" is not used in this way. One can say "看了" "看完了", but never "没看了" "没看完了". And there is a typo in your last example "么吃" -> "没吃".
    – fefe
    Commented Dec 27, 2011 at 5:32
  • I agree with fefe. 没看完了, 没吃完了, 没看了, or 没吃了 are not correct. Please consider editing your answer.
    – gonnastop
    Commented Mar 19, 2012 at 5:06

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