きる／きれない — Completely / Cannot Completely

Meaning & Usage

The grammar pattern ～きる／～きれない is formed by attaching the auxiliary verb きる — written in hiragana to distinguish it from 切きる (to cut) — to the masu-stem of a verb. It expresses two core ideas: completing an action fully and thoroughly, or being unable to complete an action due to excessive quantity, overwhelming difficulty, or limited capacity.

～きる carries a sense of pushing through to the very end — finishing a book cover to cover, depleting every last resource, or enduring hardship until the final moment. English equivalents include "to completely ~," "to finish ~ing," "to use up entirely," and "to fully ~." Effort and determination sit at the heart of this form. That is why you will find it most often in contexts of achievement and perseverance: sports commentary, graduation speeches, and self-improvement books.

～きれない (from the potential form きれる + ない) means something cannot be done completely. This comes up when there is too much to handle, when an action is emotionally or physically beyond one's capacity, or when full completion is simply impossible. Natural English translations include "cannot finish ~ing," "too much to ~," and "cannot fully ~." You will hear it constantly in everyday speech — when food portions are overwhelming, when feelings are too big for words, or when the workload is just too heavy.

Watch out for the gap between ～きれない and plain negatives like ～ない or ～られない. Those simply mean "cannot do." ～きれない is narrower: it implies you could start the action, but there is too much, or it is too difficult, to complete it fully. Getting this wrong is a common trap on the JLPT, where questions are designed to test exactly this contrast.

Some verbs pair with きる so often that the combinations have taken on specific meanings. 言いいきる means to assert something definitively, without hedging. 割わりきる means to accept a situation pragmatically and move on. 疲つかれきる means to be utterly exhausted. 乗のりきる means to get through a difficult situation entirely. All four appear regularly in native texts and on the JLPT N2 exam.

Both forms work across formal and informal contexts. In speeches and formal writing, ～きる signals determination and perseverance. In casual conversation, ～きれない comes up constantly around large quantities and overwhelming feelings. Words like 全部ぜんぶ (all), 量りょう (amount), and 一人ひとりで (alone, by oneself) often appear nearby, setting up the context of impossibility.

Structure & Formation

The pattern attaches to the masu-stem (連用形, ren'youkei) of a verb — the stem that remains when you remove ます from the polite form. Below is a summary of the key inflected forms and their meanings.

Formation examples showing masu-stem connection:

• 食たべ（ます）→ 食たべきる／食たべきれない
• 読よみ（ます）→ 読よみきる／読よみきれない
• 使つかい（ます）→ 使つかいきる／使つかいきれない
• やり（ます）→ やりきる／やりきれない
• 走はしり（ます）→ 走はしりきる／走はしりきれない
• 言いい（ます）→ 言いいきる／言いいきれない
• 持もち（ます）→ 持もちきる／持もちきれない
• 信しんじ（ます）→ 信しんじきる／信しんじきれない

The auxiliary きる attaches directly to the masu-stem without any connective particle or intervening form. The resulting compound verb conjugates like a standard Group 1 (う-verb) verb with the base き: きる (non-past), きった (past), きって (te-form), きれる (potential), きれない (negative potential).

Example Sentences

Basic Completion

Cannot Complete — Too Much to Handle

Cannot Complete — Emotional Overflow

Endurance and Perseverance

Complete Exhaustion and States

Definitive Assertion

Common Mistakes

Mistake 1: Attaching きる to the Dictionary Form Instead of the Masu-Stem

❌ 食たべるきれない ✅ 食たべきれない

This is the most common structural error. Learners unfamiliar with the masu-stem (連用形) sometimes attach きる or きれない directly to the dictionary form (終止形), producing an ungrammatical result. Always identify the masu-stem first: remove ます from the polite form and use that stem. 食たべます → 食たべ + きれない. 読よみます → 読よみ + きれない.

Mistake 2: Using きれない for Simple Inability Instead of Incomplete Completion

❌ 日本語にほんごがまだ話はなしきれない。（I can't speak Japanese yet.）

✅ 日本語にほんごがまだ話はなせない。

きれない implies you can begin the action but cannot carry it out fully or completely. It is not a general negation of ability. Saying 話はなしきれない suggests you can speak Japanese to some extent but cannot do so exhaustively — an unusual claim. For outright inability, use the standard negative potential: 話はなせない (cannot speak).

Mistake 3: Adding ことができない After きれない (Double Potential Negation)

❌ この本ほんは読よみきれないことができない。

✅ この本ほんは多おおすぎて読よみきれない。

Because きれない already encodes the negative potential meaning, adding ことができない creates a redundant double negation that is grammatically and pragmatically strange. Choose one: either Verb + きれない or, in other contexts, Verb + ことができない. They cannot be stacked.

Mistake 4: Using きれない Without a Specific Verb

❌ 量りょうが多おおすぎてきれない。

✅ 量りょうが多おおすぎて食たべきれない。

The auxiliary きれない must attach to a concrete main verb. It cannot stand alone. You must specify which action cannot be fully completed. Even when the main verb feels obvious from context, dropping it is not grammatically acceptable in standard Japanese.

Mistake 5: Confusing ～きる with ～てしまう for Completion Nuance

❌ 難むずかしい試験しけんをやりきってしまった。（intended meaning: I worked hard to complete the tough exam）

✅ 難むずかしい試験しけんをやりきった。

Both ～きる and ～てしまう express completion, but with different nuances. ～きる emphasizes complete, thorough, effortful completion — with a sense of pride or determination. ～てしまう emphasizes completion with regret, irreversibility, or unintended finality. Combining them is grammatically possible in some cases but often sounds unnatural or contradictory. Choose the one that fits the emotional tone.

Cultural Notes

Seeing something through to the very end carries genuine weight in Japanese culture, which prizes diligence and follow-through. やりきる turns up constantly in motivational settings — company pep talks, team speeches before competitions, graduation ceremonies, and self-help books. When someone says やりきった after a tough project, the pride and relief behind those words are real.

In social situations, ～きれない is a polite way to acknowledge being overwhelmed. When a host serves a generous meal and a guest says 食たべきれないです, it is not a complaint — it is appreciation. The message lands as "There is so much that I could not possibly do it justice," which reads as humble and grateful, not ungrateful.

言いいきる has an interesting cultural dimension. Japanese communication traditionally favors indirectness and hedging, so asserting something definitively — without qualification — stands out as unusually bold. In formal debates, business negotiations, and political speeches, 言いいきる signals conviction. In casual settings, though, using it too freely can sound blunt or even arrogant, depending on context and the relationship between speakers.

疲つかれきる (to be completely exhausted) describes someone who has given everything — an athlete after a race, a student after entrance exams, a parent after a brutal week. The きる suffix transforms ordinary tiredness into something total: physical and emotional reserves, fully depleted.

JLPT Tips

On the JLPT N2, these patterns appear in grammar identification, sentence completion, and reading passages. The exam focuses on nuance: can you tell the difference between "cannot do" and "cannot do completely"? Watch for sentences describing limited capacity — too much food, too many tasks — where きれない is the right choice, not ～られない or ～ない.

Pay close attention to context words that commonly appear alongside きれない: 多おおすぎる (too many/much), 量りょうが多おおい (large quantity), 一人ひとりで (alone, by oneself), とても (very, extremely). These are strong signals that きれない — rather than a plain negative form — is called for.

For the positive form, the JLPT often tests semi-fixed expressions — やりきる, 言いいきる, 乗のりきる, 疲つかれきる — in reading passages. Know their specific meanings; you cannot always guess from the main verb alone.

In sentence-arrangement tasks, remember that the masu-stem must be used — not the dictionary form, not the te-form. The pattern is simply: [masu-stem] + きる/きれない. Also remember that きれない is a potential negative, which means it inherently describes ability/inability and does not need further potential marking.

In listening sections, きれない with natural speech rhythm carries a falling intonation conveying mild helplessness or being overwhelmed. To distinguish it from 「～られない」 (standard negative potential) or 「～きない」 (a non-existent form and common distractor), listen carefully for the full vowel sequence: ki-re-na-i.