こと
(Koto)
Used at the end of a sentence to express a command, rule, or instruction.
Connection rules
- +Verb (Dictionary form) + こと
- +Verb (Nai-form) + こと
Examples
1.
夜十時までに、必ず寮に帰ること。

Yoru juu ji made ni, kanarazu ryou ni kaeru koto.
You must return to the dormitory by 10 PM.
「Dormitory rules」
2.
教室では、日本語以外は話さないこと。

Kyoushitsu de ha, nihongo igai ha hanasa nai koto.
Do not speak any language other than Japanese in the classroom.
「Language school notice」