JLPT N5 Grammar: 〜てはいけません — Polite Prohibition ("Must Not Do")

JLPT N5 Grammar: 〜てはいけません

Q: What's the difference between てはいけません and ちゃいけません?

ちゃいけません is a casual contraction of てはいけません. It's not tested at N5 but very common in spoken Japanese.

Q: Can I use てはいけません to talk about myself?

Yes, you can say 私はお酒を飲んではいけません (I must not drink alcohol) to state a personal rule or restriction.

Q: Is てはいけません always written with the kanji 行けません?

Rarely. いけません is usually written in hiragana in this pattern. The kanji 行けません is more common for the literal meaning 'can't go'.

Polite prohibition — “must not do” / “you cannot do”

JLPTジェイエルピーティー N5エヌゴ文法ぶんぽう〜てはいけません解説かいせつ (禁止きんし)

⏱️ Study time: 5–7 minutes

〜てはいけません is the polite way to say “you must not do” or “it is not allowed”. It attaches to the te‑form of a verb and adds the particle は + いけません. This pattern is essential for understanding rules, signs, and prohibitions in Japanese society.

🚀 JLPT N5 Warm-up Quiz

Q: How do you say “You must not smoke here” politely?

Answer: B (吸すってはいけません). The te‑form of 吸う + はいけません expresses strong prohibition. A is "I don't smoke here" (not a prohibition). C is a softer request "please don't smoke".

Quick Summary

Grammar Point
〜てはいけません

Meaning
Must not do / It is not allowed

Pattern
Te‑form + は + いけません

Example
ここでタバコを吸すってはいけません。ここでたばこをすってはいけません。Koko de tabako o sutte wa ikemasen.
You must not smoke here.

📝 Core Pattern

Polite prohibition: Verb (te‑form) + は + いけません

Casual: Verb (te‑form) + は + いけない

Contracted casual: 〜ちゃいけない / 〜じゃいけない (not tested at N5)

⚠️ The は in てはいけません is the same contrastive particle は, pronounced わ. Do not confuse with the direct object marker を.

🧠 Need the te‑form? See て形 (te‑form) →

💡 Toggle furigana, hiragana, or romaji for easier reading.

What is 〜てはいけません?

〜てはいけません is a polite prohibition pattern. It tells someone that an action is not permitted — “you must not do” or “it is forbidden to do”. It is formed from the te‑form of a verb + は (contrastive topic particle) + いけません (polite negative of 行く — "it won't go / it's not acceptable").

Stronger than a simple negative request (ないでください).
Often used in public rules, signs, and when enforcing regulations.
Casual form: てはいけない (less polite).

図書館としょかんで大おおきい声こえで話はなしてはいけません。としょかんでおおきいこえではなしてはいけません。Toshokan de ōkii koe de hanashite wa ikemasen.
You must not speak in a loud voice in the library.

⚡ How to Form 〜てはいけません

Verb	Te‑form	Prohibition	Meaning
書かく (kaku)	書かいて	書かいてはいけません	must not write
食たべる (taberu)	食たべて	食たべてはいけません	must not eat
する (suru)	して	してはいけません	must not do
来くる (kuru)	来きて (kite)	来きてはいけません	must not come

⚠️ Fake ichidan reminder: Verbs like 帰かえる and 入はいる are Group 1. Their te‑forms are 帰かえって and 入はいって. So: 帰かえってはいけません, not かえてはいけません.

Examples & Mini Dialogue

ここで写真しゃしんを撮とってはいけません。ここでしゃしんをとってはいけません。Koko de shashin o totte wa ikemasen.
You must not take photos here.

✅ Common in museums and restricted areas.

授業中じゅぎょうちゅうにスマホを使つかってはいけません。じゅぎょうちゅうにすまほをつかってはいけません。Jugyōchū ni sumaho o tsukatte wa ikemasen.
You must not use your smartphone during class.

🗣️ Mini Dialogue
A: ここで走はしってもいいですか。ここではしってもいいですか。Koko de hashitte mo ii desu ka.
B: いいえ、走はしってはいけません。いいえ、はしってはいけません。Iie, hashitte wa ikemasen.

⚡ てはいけません vs ないでください

Pattern	Strength	Usage	Example
〜てはいけません	Strong prohibition (rule / law)	Public signs, strict rules	入はいってはいけません。 You must not enter.
〜ないでください	Soft request (please don't)	Personal requests, polite reminders	入はいらないでください。 Please don't enter.

Common Mistakes (and Fixes)

✕ 帰かえてはいけません。

✓ 帰かえってはいけません。 (帰る is Group 1; te‑form is 帰って.)

✕ ここに入いれてはいけません。

✓ ここに入はいってはいけません。 (入る is "hairu", not "iru" with that meaning.)

✕ Using てはいけません for personal requests (too strong).

✓ Use ないでください for softer requests.

JLPT N5 Practice Questions

Score: 0 / 3

1. “You must not eat here.” Choose the correct polite prohibition.

2. Which form is correct for 入はいる (to enter)?

3. てはいけません is __________ than ないでください.

🎯 JLPT N5 tip: The prohibition pattern 〜てはいけません appears in both the grammar and reading sections. It's often tested alongside permission (〜てもいいですか). If you can distinguish strong prohibition from soft request, you'll avoid a common trap.

Test yourself with a free mock exam →

About the Instructor

Taught by Anup Sensei at Gogaku Language & Training Center in Pokhara. With real Japan experience and a focus on exam essentials, he helps students pass the JLPT with confidence.

⚡ Vocabulary Used in This Lesson

Japanese	Reading	Type	English Meaning
書かく	かく	Godan verb	to write
食たべる	たべる	Ichidan verb	to eat
吸すう	すう	Godan verb	to smoke
入はいる	はいる	Godan verb (fake ichidan)	to enter
帰かえる	かえる	Godan verb (fake ichidan)	to return, to go home
走はしる	はしる	Godan verb (fake ichidan)	to run
タバコ	たばこ	Noun	tobacco, cigarette
図書館としょかん	としょかん	Noun	library
写真しゃしん	しゃしん	Noun	photo, picture
撮とる	とる	Godan verb	to take (a photo)

Related Grammar

Frequently Asked Questions

What's the difference between てはいけません and ちゃいけません?

ちゃいけません is a casual contraction of てはいけません (e.g., 入はいっちゃいけません). It's not tested at N5 but very common in spoken Japanese.

Can I use てはいけません to talk about myself?

Yes, you can say 私わたしはお酒さけを飲のんではいけません (I must not drink alcohol) to state a personal rule or restriction.

Is てはいけません always written with the kanji 行けません?

Rarely. いけません is usually written in hiragana when used in this pattern. The kanji 行けません is more common for the literal meaning "can't go".

Continue Learning

Next: ないでください — making polite negative requests.

Learn ないでください →

→ Explore the JLPT N5 Grammar Hub

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