N3 Advice, Obligation, and Prohibition

~こと: meaning, usage and examples

~こと means: you must... (used for rules or strong commands).

Updated 9 November 2026 · By the My Senpai team · Spotted a mistake? Tell us

Examples

1. 部屋へやに入はいる前まえは、必かならずノックすること。

   Be sure to knock before entering the room.

2. 図書館としょかんでは、静しずかにすること。

   You must be quiet in the library.

3. 試験しけん中ちゅうは、携帯けいたい電話でんわの電源でんげんを切きること。

   Turn off your cell phone during the exam.

4. 使つかったコップは、自分じぶんで洗あらうこと。

   Wash any cups you use yourself.

When to use it

こと at the end of a sentence states a rule or an instruction: "must," "be sure to," "do not." It appears on signs, school and dorm rules, exam instructions, and memos: 名前なまえを書かくこと ("Write your name"), 廊下ろうかを走はしらないこと ("No running in the halls"). Teachers also use it when listing what students must do.

Nuance

Written and impersonal, a little strict. It is used by people in authority and in official notices. It sounds cold in normal conversation, and you cannot use it toward someone above you.

Compare

ように is a spoken, indirect instruction: 早はやく来くるように. ことだ gives personal advice: 休やすむことだ ("You should rest"). こと without だ is a rule for everyone. なさい is a direct spoken command.

Tip: Check the last word on a Japanese notice. If a sentence ends in こと, read it as a rule, not a suggestion.