Hello Japanese learners!
I’m Miyabi, a Japanese mom.
The expression 「〜てしまった」 is extremely common in Japanese, but doesn’t it feel confusing because it has so many meanings?
Sometimes it means “finished”, and other times it expresses regret.
If you don’t understand this difference, misunderstandings can easily happen in real conversations.
In this article, I will clearly and thoroughly explain the three main nuances of 「〜てしまった」, using example sentences that I actually use in daily life.
Two Core Functions of 「〜てしまった」
The usage of 「〜てしまった」 can broadly be divided into two main functions
1.Completion of an action or change
→ Something is completely finished.
2.The speaker’s emotion
→ Feelings such as regret, disappointment, or frustration about what has been completed.
However, these categories are not always clearly separated.
Sometimes they overlap, and honestly, Japanese is an ambiguous language. Depending on the situation and context, the nuance can shift slightly.
So even as a native speaker, I can’t always say “This is 100% this meaning.”
Still, I’ll explain it as clearly as possible.
Let’s look at the specific nuances.
1. Completion / Accomplishment / Handling Something
Meaning & Nuance
This usage indicates that an action or change has been fully completed.
It strengthens the verb in the direction of finishing, dealing with, or clearing something.
Examples
• レポートは昨日までに全部書いてしまった。(れぽーとは きのうまでに ぜんぶかいてしまった)
→ I finished writing the entire report by yesterday.
• 「まずはご飯を食べてしまおう。遊ぶのはそれからね。」(「まずは ごはんを たべてしまおう。あそぶのは それからね)」
→ Let’s finish eating first. We’ll play after that.
・引越しで、古い家具を全部捨ててしまった。(ひっこしで ふるいかぐを ぜんぶすててしまった)
→ When I moved, I got rid of all the old furniture.
・図書館の本は全部読んでしまった。(としょかんのほんは ぜんぶよんでしまった)
→ I read all the library books (completely).
2. Regret / Disappointment / Blame (Negative Feelings)
Meaning & Nuance
This usage includes negative emotions such as regret, disappointment, failure, or even blame toward someone else.
It is used when the result is undesirable or goes against one’s intention.
Examples
• 電車の時間を間違えて、乗り遅れてしまった。(でんしゃの じかんを まちがえて、のりおくれてしまった)
→ I got the train time wrong and missed it. (regret / mistake)
• 大事な書類を家に忘れてしまった。(だいじな しょるいを いえに わすれてしまった)
→ I forgot an important document at home. (mistake / trouble)
• （子どもに向かって）全部一人で食べてしまったの？(こどもにむかって)(ぜんぶひとりで たべてしまったの？)
→ (To a child) You ate everything by yourself? (blame / disappointment)
3. Uncontrollable Emotional Reactions
Meaning & Nuance
This expresses something that happens naturally and unintentionally, regardless of the speaker’s will.
When 「〜てしまう」 is attached to emotion-related verbs like cry or laugh, it usually has this meaning.
Examples
• 彼の面白い話を聞いて、思わず笑ってしまった。(かれの おもしろいはなしを きいて、おもわず わらってしまった)
→ I couldn’t help laughing when I heard his funny story.
• 夫の優しさに泣いてしまった。(おっとの やさしさに ないてしまった)
→ I ended up crying because of my husband’s kindness.
4. Mixed Type: Even Native Speakers Find This Hard to Categorize
Some sentences are difficult to classify into just one category, even for Japanese people.
Examples
• 貯金していたお金を、旅行で全部使ってしまった。(ちょきんしていたおかねを、りょこうで ぜんぶ つかってしまった)
→ I spent all the money I had saved on a trip.
(completion + regret?)
• チャンスはもう逃してしまったから、諦めるしかない。(ちゃんすは もう のがしてしまったから、あきらめるしかない)
→ I’ve already missed the chance, so I have no choice but to give up.
(completion + regret?)
・つい怒ってしまった。(ついおこってしまった)
→ I ended up getting angry.
(natural reaction + regret?)
These examples show that 「〜てしまった」 cannot always be neatly categorized.
As with all Japanese, context and situation matter more than anything else.
This phrase also appears in this video, so be sure to check it out!
