JLPT N1Spoken and writtenStrong feeling

ても～きれないcan never … enough

The same verb twice: however much you thank, apologize or regret, it will never be enough. The feeling is bigger than anything you can do about it.

私わたしはあの日ひの判はん断だんを、どれほど悔くやんでも悔くやみきれない。

However much I regret the decision I made that day, it will never be enough.

どれほどご支し援えんに感かん謝しゃしても、感かん謝しゃしきれません。

I cannot thank you enough for your support.

How to form it

Verb て-form + も + the same verb's ます-stem + きれない

With a する verb the noun is usually said once: 感かん謝しゃしてもしきれない. Often with いくら or どれほど in front. Also written 切きれない.

Goes with: A few verbs of feeling: 感かん謝しゃする (thank), 謝あやまる (apologize), 悔くやむ and 後こう悔かいする (regret), 泣なく (cry).
Said about: Your own feeling, over something that matters: a great kindness, a serious mistake.
Where you'll meet it: Speeches, letters, apologies, interviews after a defeat, and conversation at a serious moment.
More lightly: 本ほん当とうにありがとう, すごく後こう悔かいしている.

In use

お世せ話わになった先せん生せいには、感かん謝しゃしてもしきれません。

I can never thank my teacher enough for everything.

今こん回かいご迷めい惑わくをおかけしたことは、いくら謝あやまっても謝あやまりきれません。

I can never apologize enough for the trouble I have caused you this time.

一いっ点てん差さで負まけるなんて、泣ないても泣なききれない。

To lose by a single point: I could cry and cry and it still wouldn't be enough.

With an amount, there is no feeling in it

After 数かぞえる or 読よむ it only says there is too much to finish.

倉そう庫この箱はこは、一いち日にち中じゅう数かぞえても数かぞえきれなかった。

There were too many boxes in the warehouse to count, even with a whole day at it.

切きっても切きれない is a phrase of its own

"Inseparable": here 切きれない is "can't be cut".

この町まちの歴れき史しは、川かわと切きっても切きれない関かん係けいにある。

This town's history can't be separated from the river.

Other forms for a feeling or quality at its extreme

極まる・極まりないN1

A な-adjective, nearly always a harsh verdict: 失しつ礼れい極きわまる, 危き険けん極きわまりない. The two mean the same.

その発はつ言げんは無ぶ礼れい極きわまりない。

That remark is outrageously rude.

の極みN1

A noun for a state, good or bad: 贅ぜい沢たくの極きわみ, 疲ひ労ろうの極きわみ.

連れん日じつの徹てつ夜やで、担たん当とう者しゃは疲ひ労ろうの極きわみにあった。

After night after night without sleep, the person in charge was utterly exhausted.

の至りN1

A handful of nouns in ceremonial thanks and apology: 光こう栄えいの至いたり, 恐きょう縮しゅくの至いたり.

今こん回かい、栄えい誉よある賞しょうを賜たまわり、光こう栄えいの至いたりです。

I could not be more honored to receive this distinguished award.

を禁じ得ないN1

A noun for a feeling that wells up: 同どう情じょう, 怒いかり, 涙なみだ. Written.

被ひ災さい地ちから届とどいた証しょう言げんに、深ふかい同どう情じょうを禁きんじ得えない。

I cannot help feeling deep sympathy at the accounts coming out of the disaster area.

てやまないN1

A verb for a lasting wish or regard: 願ねがってやまない, 尊そん敬けいしてやまない. Speeches and letters.

私わたくしどもは、母ぼ校こうのさらなる発はっ展てんを願ねがってやみません。

We sincerely wish our old school every further success.

Close neighbours

切る・切れないN3

By itself きれない is a plain "can't finish".

この量りょうは一人ひとりでは食たべ切きれません。

This is too much for one person to finish.

Check yourself

1What does this mean?

助たすけてくれた友ゆう人じんには、いくら感かん謝しゃしてもしきれない。

Choose an answer to see why.

2Which one fits?

大たい切せつな書しょ類るいをなくしてしまい、いくらお詫わびしても（　　）。

Choose an answer to see why.

More detail

死しんでも死しにきれない is a set phrase: you couldn't die in peace.

この店みせを息子むすこに譲ゆずるまでは、死しんでも死しにきれない。

I can't die in peace until I've handed this shop over to my son.

More sentences

この美び術じゅつ館かんの収しゅう蔵ぞう品ひんは、一いち日にちかけて見みても見みきれない。

This museum has more in its collection than you could see in a whole day.

問とい合あわせが多おおく、全ぜん員いんで対たい応おうしても対たい応おうしきれません。

There are so many inquiries that even the whole team can't keep up with them.

どれほど言こと葉ばを尽つくして説せつ明めいしても、説せつ明めいしきれない部ぶ分ぶんがある。

However carefully you explain, there are parts that can't be fully put into words.