～こと

• Reading: こと
• Romaji: koto
• Formation: Verb dictionary form + こと (affirmative command) / Verb ない-form + こと (negative command)

Meaning

An auxiliary noun used at the end of a sentence to express a command, instruction, or rule. It functions as a written directive commonly found in regulations, notices, and instructions.

When こと appears at the end of a sentence following a verb in its dictionary form (affirmative) or ない form (negative), it functions as a formal written command or instruction. This usage is distinct from こと as a simple nominaliser. It is characteristic of official notices, school rules, workplace regulations, exam instructions, and signs. For example, 静かにすること means 'Be quiet' as a rule. The tone is impersonal and authoritative — it states what must or must not be done without addressing anyone in particular. It is not used in conversation. Learners should recognise it in written instructions but use てください or なさい for spoken commands.

Examples

1. レポートは金曜日までに提出すること。 Submit reports by Friday.
2. 試験中は辞書を使用しないこと。 Do not use dictionaries during the examination.
3. 廊下を走らないこと。 Do not run in the corridors.

Usage Guide

Context: written, official notices, rules and regulations

Tone: directive

Do Say

• 申込書にはすべての欄を記入すること。
• 館内では携帯電話を使用しないこと。
• 退室時は必ず消灯すること。

Don't Say

• 早く寝ること。(Using こと as a spoken command to a specific person — this form is for impersonal written rules, not direct speech) → 早く寝なさい。
• 明日来ること。(Using こと in casual spoken instruction — use て form or なさい instead) → 明日来てください。

Origin & History

こと originally means 'thing' or 'matter' and functions as a nominaliser. In this directive use, the sentence-final こと transforms the verb phrase into an impersonal rule or instruction — literally stating the 'matter' that should be done.

Cultural Context

Generation: All ages

Social background: Universal