ちゃいけない・じゃいけない
🃏 Flashcard
ちゃいけない・じゃいけない
cha ikenai / ja ikenai
Tap to reveal usage
must not do (spoken Japanese)
N5
Tap to test your recall · +10 XP
📊 Pattern Stats
JLPT Level
N5
Beginner · Basic sentence structures
Reading
cha ikenai / ja ikenai
Post ID
50602
Patterns today
0
0 / 10 daily goal
📝 Usage Notes
must not do (spoken Japanese)
📖 How to use it
Expresses prohibition in casual spoken Japanese, equivalent to 'must not do'.
Attaches to
Attach to the て-form of verbs. If the て-form ends in で, replace で with じゃ; otherwise replace て with ちゃ. Then add いけない.
This pattern is the casual spoken version of てはいけない. It tells someone they are not allowed to do something, or that doing it is bad. Use it with friends or people younger than you, not in formal situations.
To form it, take the て-form (like 食べて, 行って) and change the ending: て becomes ちゃ, で becomes じゃ. Then add いけない. For example, 食べて -> 食べちゃいけない, 行って -> 行っちゃいけない. For verbs like 飲んで, it becomes 飲んじゃいけない.
You'll hear this a lot in everyday speech, like a parent telling a child 'Don't touch that!' or a friend saying 'You can't go in there.' It's strong, so use it carefully.
ここでタバコを吸っちゃいけないよ。
Koko de tabako o sutte cha ikenai yo.
You can't smoke here.
宿題を忘れちゃいけない。
Shukudai o wasure cha ikenai.
You must not forget your homework.
そのケーキを食べちゃいけない？
Sono keeki o tabe cha ikenai?
Can't I eat that cake?
Not てはいけない
てはいけない is the polite\/written form; ちゃいけない is casual and spoken. Use てはいけない in formal writing or with superiors.
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Casual spoken Japanese; not used in formal writing or polite speech.
🎯 Quick Quiz
What does this grammar pattern mean or do?
ちゃいけない・じゃいけない
📚 How to Master This Pattern
Say It Aloud
Press Hear it and repeat ちゃいけない・じゃいけない three times. Feel the rhythm — grammar patterns have a natural flow.
Flip Before Reading
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Write Two Sentences
Compose two original sentences using ちゃいけない・じゃいけない. One about yourself, one about something you see right now.
Spaced Review
Save this pattern and revisit at 10 min, 1 day, 3 days. Production (writing) beats recognition for grammar.
🔗 More JLPT N5 Patterns
❓ Frequently Asked Questions
What does the grammar pattern ちゃいけない・じゃいけない mean?
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Must not do (spoken Japanese)
What JLPT level is ちゃいけない・じゃいけない?
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Nihoner currently groups this pattern under JLPT N5 — Beginner · Basic sentence structures. Use the level label as study guidance rather than a prediction of what will appear on an exam.
How do you use ちゃいけない・じゃいけない in a sentence?
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Attach ちゃいけない・じゃいけない (cha ikenai / ja ikenai) to the appropriate verb or noun form as described in the usage notes. Then try writing two original sentences — one about yourself and one about something around you.
Is ちゃいけない・じゃいけない formal or casual Japanese?
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ちゃいけない・じゃいけない is used in both casual and polite contexts. It appears frequently in everyday conversation, textbooks, and simple written materials.
How can I remember ちゃいけない・じゃいけない long-term?
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Use the flashcard on this page for active recall — see the pattern, reconstruct the usage from memory, then flip. Follow with the 4-choice quiz to distinguish it from similar patterns. Review later the same day and again over the following days. Writing original sentences can help you practise using the pattern in context.