Using "must not" for Prohibition

A2 Eiken Pre-2 Elementary

must not + base verb

Explanation

Use "must not" to say that something is not allowed. It is common in rules, signs, and safety instructions.

For example, "You must not touch the stove." Here "You" is the person, "must not" shows a strong prohibition, and "touch the stove" is the action that is not allowed. In Japanese, this is like "〜してはいけません." After "must not," use the base verb, so do not add "to" or "-ing."

Examples

  • You must not smoke here. ここではタバコを吸ってはいけません。
  • Students must not use their phones in class. 生徒は授業中にスマホを使ってはいけません。
  • We must not open this door. 私たちはこのドアを開けてはいけません。
  • Must we not bring food into the lab? 研究室に食べ物を持ち込んではいけませんか。
  • You must not park in front of the gate. 門の前に駐車してはいけません。
  • The app says you must not share your password. そのアプリでは、パスワードを共有してはいけないと書いてあります。

Common Mistakes

Japanese learners often write "You must not to smoke here." or "You don't must smoke here." The correct form is "You must not smoke here." After "must not," use the base verb only, with no "to" and no "do".

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