〜きる: Doing Something Completely / To the End
What it means
〜きる (written 〜切る as a suffix) is built from the verb 切る ("to cut"), but as a suffix it no longer means cutting. It does two related jobs:
- Finish an action completely — carry it through to the very end, with nothing left over.
- Reach a state fully / to the extreme — be in a condition utterly, completely.
In both cases the nuance is thoroughness: not just doing something, but doing it all the way.
ヤッタンは大盛りのカレーを食べきった。
ヤッタンは おおもりの カレーを たべきった。
Yattan ate up the whole large serving of curry.
食べる + きる = eat it all, leaving nothing.
モチはマラソンを最後まで走りきった。
モチは マラソンを さいごまで はしりきった。
Mochi ran the marathon all the way to the end.
走りきる = run completely to the finish.
先生は疲れきった顔をしていた。
せんせいは つかれきった かおを していた。
The teacher had a completely exhausted look on her face.
疲れきる = be utterly worn out — a state taken to the extreme.
How to form it
Take the verb's ます-stem (the form before ます) and attach きる. The whole thing then conjugates as a regular う-verb (it ends in る but behaves like 切る → 切った, 切って):
| Verb | ます-stem | + きる | Meaning |
|---|---|---|---|
| 食べる (eat) | 食べ | 食べきる | eat it all up |
| 使う (use) | 使い | 使いきる | use up entirely |
| 読む (read) | 読み | 読みきる | read all the way through |
| 疲れる (tire) | 疲れ | 疲れきる | be utterly exhausted |
Because it conjugates like an う-verb, the past is 〜きった and the て-form is 〜きって:
貯金を使いきってしまった。
ちょきんを つかいきって しまった。
I ended up using up all my savings.
使いきって + しまった — stacks naturally with 〜てしまう.
The negative: 〜きれない
The potential-negative form 〜きれない ("cannot finish …-ing" / "too … to …") is at least as common as the positive. It says the action is too much to complete:
量が多すぎて、一人では食べきれない。
りょうが おおすぎて、ひとりでは たべきれない。
There's too much — I can't finish it on my own.
食べきれない = can't eat it all up.
弟は覚えきれないほどの単語を一晩で出された。
おとうとは おぼえきれない ほどの たんごを ひとばんで だされた。
My little brother was given more vocabulary words in one night than he could possibly memorize.
覚えきれないほどの = more … than one can memorize.
The pattern 〜きれないほどの + noun ("more … than you can …") is a set phrase worth memorizing: 数えきれないほどの星 ("more stars than you can count").
How it differs from 〜てしまう
Both can translate as "finish," so learners mix them up. The difference is what each emphasizes:
- 〜きる stresses completeness — every last bit, to the end. Often positive: an achievement (走りきった = ran the whole way).
- 〜てしまう stresses completion as a done deal, often with regret or "oops" (食べてしまった = ate it / ended up eating it, possibly shouldn't have).
You can even combine them: 使いきってしまった ("I went and used it all up") layers both nuances.
Note that 〜きる is a suffix on a stem, not a standalone verb. Don't confuse it in plain text with the ordinary verb 切る ("to cut"), which takes its own object: 紙を切る ("cut the paper").
Common mistakes
- Using the て-form or dictionary form instead of the ます-stem. It attaches to the stem: 食べきる (✓), not 食べて切る or 食べる切る (✗).
- Misreading 〜きれない as "cut." きれない here is the potential negative "can't finish," not "can't cut": 読みきれない = "too long to finish reading," not "can't cut."
- Forcing it onto every verb. 〜きる wants verbs with a natural endpoint or limit (food, distance, supplies, energy). 死にきる or 知りきる sound odd; stick to verbs where "completely / to the end" makes sense.
- Conjugating it like an る-verb. It follows 切る (an う-verb): past is 〜きった, not 〜きた.
Quick recap
- ます-stem + きる = do the action completely / to the very end: 食べきる, 走りきる, 使いきる.
- Also marks a state taken to the extreme: 疲れきる, 困りきる.
- Conjugates as an う-verb: 〜きった, 〜きって.
- Negative 〜きれない = "can't finish" / "too … to": 食べきれない, 覚えきれないほどの単語.
- Emphasizes completeness; compare with 〜てしまう (completion, often regret).
Your turn
Choose the correct 〜きる / 〜きれない form for each sentence.
Start the 5-question drill →Frequently asked questions
What does 〜きる mean?
Attached to a verb's ます-stem, it means doing the action completely or all the way to the end: 食べきる ('eat it all up'), 走りきる ('run the whole way'). It can also mean reaching a state fully: 疲れきる ('be utterly exhausted').
What's the difference between 〜きる and 〜てしまう?
〜きる stresses completeness — every last bit, to the end, often a positive achievement. 〜てしまう stresses that something is done and over, often with regret. You can combine them: 使いきってしまった.
What does 〜きれない mean?
It's the potential-negative of 〜きる: 'cannot finish' or 'too … to.' 食べきれない = 'I can't finish eating it.' The set phrase 〜きれないほどの means 'more … than one can …': 数えきれないほどの星 ('countless stars').
Is 〜きる the same as the verb 切る ('to cut')?
It comes from 切る and conjugates the same way (〜きった, 〜きって), but as a stem suffix it means 'completely,' not 'cut.' The standalone verb 切る takes its own object: 紙を切る ('cut the paper').