Introduction
In this blog, we’ll look at how to use -てしまう (-te shimau), a useful structure with two meanings. It can express completing an action or indicate regret over something happening unintentionally.
What It Means
- -てしまう can mean “to finish doing” or “do something completely”.
For example:
本を読んでしまいました。
(Hon o yonde shimaimashita.)
I finished reading the book. - -てしまう can also express “regret” or “doing something unintentionally”.
For example:
電車の中にスマホを忘れてしまいました。
(Densha no naka ni sumaho o wasurete shimaimashita.)
I accidentally left my phone on the train.
When You Use It
Use -てしまう to show determination when finishing an action or to express regret when something unexpected happens. How it’s interpreted depends on the context.
Examples
- 宿題を忘れてしまいました。
(Shukudai o wasurete shimaimashita.)
I accidentally forgot my homework. - ケーキを全部食べてしまいました。
(Keeki o zenbu tabete shimaimashita.)
I ate the entire cake.
Contracted Forms
In casual speech, –てしまう (-te shimau) changes to –ちゃう (-chau), and –でしまう (-deshimau) changes to –じゃう (-jau). Here are some examples to see the difference:
- 食べてしまいました→食べちゃいました
(Tabete shimaimashita → Tabechaimashita.)
I ate it all. - 食べてしまった→食べちゃった
(Tabete shimatta → Tabechatta.)
I ate it all. - 飲んでしまいました→飲んじゃいました
(Nonde shimaimashita → Nonjyaimashita.)
I finished drinking. - 飲んでしまった→飲んじゃった
(Nonde shimatta → Nonjatta.)
I drank it all.
Note
You can’t use -てしまう with negative verbs. This means you cannot express “regrettably, something did not happen” with -しまう.
Corret:
かぎをなくしてしまいました。
(Kagi o nakushite shimaimashita.)
I lost my key.
Incorrect:
かぎをなくさなかったしまいました。
(Kagi o nakusanakatta shimaimashita.)
Trying to express “Unfortunately, I did not lose my key.”
Conclusion
Now you know how to use -てしまう to talk about actions you complete or situations you regret.
Recommended Resources
For a deeper understanding of -てしまう (-te shimau), I recommend “A Dictionary of Basic Japanese Grammar.”This book offers clear explanations and examples that cover the nuances of this grammar point, including expressing regret and completing actions unintentionally.
