てしまう means completion and regret. It is a JLPT N4 Japanese grammar pattern used to show that an action is finished completely or happened with regret.
This grammar point often appears in daily conversation, stories, apologies, and JLPT N4 reading passages. If you want to say that something was completed or happened accidentally with an “oops” feeling, てしまう is a useful pattern to learn because it helps you read Japanese with more precision.
What does てしまう mean?
Use てしまう when you want to describe either full completion or an action the speaker feels bad about.
Natural translations include:
- do completely
- end up doing
- unfortunately do
How to form てしまう
Examples of the pattern:
- 食べてしまう
- 忘れてしまう
- 読んでしまう
When is てしまう used?
Use てしまう in situations like:
- saying an action is completely finished
- expressing regret about a mistake
- describing an accidental or unwanted result
Tone and register:
- neutral; ちゃう and じゃう are casual contractions
- Common in conversation, narratives, apologies, and textbook examples
てしまう example sentences
After reading each sentence, ask what job てしまう is doing: completion, limitation, soft denial, or summarizing a conclusion.
Nuance of てしまう
The key nuance is completion plus possible regret, depending on context.
For example:
- In apologies or mistakes, it sounds regretful or apologetic.
- Compared with ちゃう・じゃう, it feels more complete and less casual.
てしまう vs ちゃう・じゃう
Common mistakes with てしまう
A helpful practice method is to write one sentence with てしまう, then rewrite it with ちゃう・じゃう.
Is てしまう on the JLPT?
Yes. てしまう is commonly taught as JLPT N4 grammar.
- recognize it in reading
- understand its nuance in context
- use it in simple original sentences
For test preparation, study the grammar point in full sentences. JLPT questions often test whether you understand the surrounding context, not just the dictionary meaning.
Practice questions for てしまう
Learning path for てしまう
Use てしまう as part of your JLPT N4 て-form action-flow and auxiliary verb grammar toolkit. Review the main て-form action first, then ask what the auxiliary adds: preparation, trial, completion, regret, movement, continuation, or a change over time. Build short verb chains before using longer sentences.
Related grammar to review next
- てしまう / ちゃう — finish completely; do accidentally.
- 終わる — finish doing.
- ておく — do in advance; leave done.
- てみる — try doing.
Browse more lessons here:
Learn てしまう with Hane
If you want to review てしまう together with the related patterns above, Hane helps you practice Japanese in short, focused sessions.
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FAQ about てしまう
What does てしまう (te shimau) mean in Japanese?
てしまう (te shimau) means “completion and regret”. It is JLPT N4 grammar. Use てしまう when you want to describe either full completion or an action the speaker feels bad about.
How do you form てしまう (te shimau)?
Verb て-form + しまう Verb で-form + しまう
What is an example sentence with てしまう (te shimau)?
宿題を全部してしまいました。 — I finished all of my homework.