# ないといけない: must do > Learn how to use ないといけない, a JLPT N5 Japanese grammar point meaning must do, with structure, nuance, examples, mistakes, and comparisons. JLPT level: N5 · Updated: 2026-05-17 · Canonical: https://hane-app.com/blog/n5-naito-ikenai/ **ないといけない** means **must do**. It is a **JLPT N5** Japanese grammar pattern used to express obligation or necessity. This grammar point appears often in beginner conversations, classroom Japanese, and JLPT-style questions. If you want to say that an action is required, **ないといけない** is a useful pattern to learn because it helps you build natural basic sentences. ## What does ないといけない mean? Use **ないといけない** when you want to show that someone has an obligation to do something. Natural translations include: - must - have to - need to The exact English translation changes with context. Focus on the role of the grammar point in the sentence first, then choose the English phrase that sounds natural. ## How to form ないといけない
Verb negative stem + ないといけない
Verb negative stem + ないといけません
Examples of the pattern: - 行いかないといけない - 勉強べんきょうしないといけない - 早はやく寝ねないといけない Pay attention to the word form before and after the pattern. Many beginner mistakes happen because the meaning is understood, but the grammar is attached to the wrong form. ## When is ないといけない used? Use **ないといけない** in situations like: - talking about obligations - saying what is necessary - explaining duties or requirements Tone and register: - neutral and conversational; ないといけません is polite - Common in daily speech, textbook examples, and beginner JLPT questions ## ないといけない example sentences
明日あした早はやく起おきないといけない。
I have to wake up early tomorrow.
obligation
宿題しゅくだいをしないといけません。
I must do my homework.
polite
病院びょういんに行いかないといけない。
I have to go to the hospital.
obligation
パスポートを持もって行いかないといけません。
I have to bring my passport.
polite
もっと勉強べんきょうしないといけない。
I need to study more.
obligation
Read the Japanese sentence first, then check the English translation. Try to notice what the grammar point contributes: question, contrast, reason, time limit, suggestion, negation, or obligation. ## Nuance of ないといけない The key nuance is **necessity based on a rule, situation, or responsibility**. This matters because beginner Japanese often uses small words and endings to show meaning that English expresses with word order or helper verbs. For **ないといけない**, the sentence can change a lot depending on placement and context. For example: - In conversation, it sounds practical and obligation-focused. - Compared with **なければならない**, it feels more conversational and common in speech. ## ないといけない vs なければならない Both **ないといけない** and **なければならない** can express related ideas, but they are different.
ないといけない
common way to say must or have to
comes from “if you do not do it, it will not be okay”
勉強べんきょうしないといけない。
I have to study.
vs
なければならない
more formal or textbook-like
often appears in writing and formal explanations
勉強べんきょうしなければならない。
I must study.
If you are unsure which one to use, ask what the sentence is trying to do: ask a question, connect ideas, show a reason, mark time, make an invitation, or express obligation. ## Common mistakes with ないといけない
❌ 行いくないといけない
✅ 行いかないといけない

Using dictionary form before ないといけない. Attach the pattern to the negative stem instead.

❌ 病院びょういんに行いってはいけない
✅ 病院びょういんに行いかないといけない

Confusing obligation with prohibition patterns like てはいけない.

❌ 食たべなかったといけない
✅ 食たべないといけない

Using the past negative instead of the present negative stem.

📝
Remember that ないといけない expresses obligation, while てはいけない expresses prohibition. The meaning flips completely.
A helpful practice method is to write one sentence with **ないといけない**, then rewrite it with **なければならない**. If the meaning or tone changes, explain that difference in your own words. ## Is ないといけない on the JLPT?
N5

Yes. ないといけない is commonly taught as JLPT N5 grammar.

That means learners should be able to:

  • Recognize it in reading
  • Understand its nuance in context
  • Use it in simple original sentences

For test preparation, do not only memorize the English gloss. Practice identifying the words around the grammar point, because JLPT questions often test structure and context together.

## Practice questions for ないといけない
1 Say you have to wake up early. obligation
2 Say you must do homework. obligation
3 Say you need to bring a passport. obligation
Keep the sentences short at first. Once the form feels natural, add time words, places, reasons, or contrast to make the sentence more realistic. ## Learning path for ないといけない
1 Practice forming ないといけない from the negative stem until you can do it without thinking.
2 Compare it with なければならない to feel the difference between casual speech and formal writing.
3 Write three short sentences: one plain, one with a time word, and one with a different subject.
4 Contrast it with なくてはいけない and なくちゃ to see how the tone softens.
5 Switch the ending to ないといけません and practice using it in polite conversations.
## Related grammar to review next - [なくてはいけない](/blog/n5-nakute-wa-ikenai/) — contrasts request, permission, prohibition, advice, and obligation strength. - [なくてはならない](/blog/n5-nakute-wa-naranai/) — contrasts request, permission, prohibition, advice, and obligation strength. - [なくちゃ](/blog/n5-nakucha/) — contrasts request, permission, prohibition, advice, and obligation strength. - [なくてもいい](/blog/n5-naku-temo-ii/) — contrasts request, permission, prohibition, advice, and obligation strength. ## Learn ないといけない with Hane If you want to review **ないといけない** together with the related patterns above, Hane helps you practice Japanese in short, focused sessions. Browse more lessons here: - [All grammar lessons](/blog/) - [JLPT N5 grammar lessons](/blog/n5/)