ことになっている
- 1It is a rule, regulation, or established custom that someone does (or does not do) something.Ex. 1
- 2It has been arranged or scheduled that something will happen; someone is supposed to do it.Ex. 2
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Neutral in register, common for company or school rules, laws, customs, and fixed appointments, including when explaining rules to others. It presents an already settled state, often decided by others or by mutual agreement, as a fact. Unlike ことにしている, which reports a habit one has personally chosen, it frames the matter as externally fixed.
Learners often use ことになっている for a personal habit they chose themselves, where ことにしている is correct.
Note that ことになっていた often implies something was supposed to happen but may not have.
Do not confuse it with ことになる, which describes a decision or outcome coming about, not an established state.
- ことになるN4「ことになる」 means a matter gets settled or boils down to a certain result; new decisions are often reported with 「ことになりました」, and it can also express calculation such as 'equals...'. By contrast, 「ことになっている」 describes established rules or arrangements that remain in effect.
- 〜ことにしているN3「ことにしている」 refers to habits, principles, or plans you persistently follow based on your own decision, while 「ことになっている」 stems from rules, customs, or pre-agreed arrangements. They attach to verbs the same way, so remember: self-made habits take 「ことにしている」.
- ことにするN4「ことにする」 expresses the subject making a decision by their own volition, and additionally carries the sense of 'pretend/just treat it as'; 「ことになっている」 states a rule or agreed arrangement rather than a personal choice. The two are not interchangeable—for personal persistent habits, use 「ことにしている」.
- 予定だN4「予定だ」 overlaps only regarding fixed arrangements—it simply states a schedule and attaches after 名詞+の—whereas 「ことになっている」 more strongly conveys prior agreement and being bound by it. When speaking of rules or customs, you cannot substitute 「予定だ」.
ことになる and ことにする describe a decision being made (by circumstances or others vs. by oneself), while ことになっている and ことにしている describe the resulting ongoing state: an external rule or arrangement vs. a personal habit. 予定だ states that something is planned or scheduled, whether for oneself, others, or an event, without indicating how it was decided, whereas ことになっている presents it as a settled arrangement and can also express rules and customs, which 予定だ cannot.
