ことになっている
Supposed To/Established Rule
ことになっている is used to state that something is 'supposed to' happen or is 'the rule.' It focuses on the current state of an arrangement, regulation, or schedule rather than the act of deciding it.
How It Works
The pattern ことになっている (polite form: ことになっています) is formed by combining the nominalizer こと with the resultative form of the verb なる (to become). It directly follows the Dictionary form or Nai-form of verbs. For nouns and adjectives, it connects using Noun / な-adjective + (だ)ということになっている or い-adjective + ということになっている.
While ことになる focuses on the moment a decision is made, ことになっている focuses on the ongoing state of that decision. It implies that the decision was made by someone else, a group, or society at large, and the speaker is simply reporting the current reality.
Key Usage Areas:
- Rules and Laws: 'In Japan, you are supposed to drive on the left.'（日本では車は左側を走ることになっている）
- Social Customs: 'In this house, we take off our shoes.'（この家では靴を脱ぐことになっている）
- Schedules/Appointments: 'I am supposed to meet my teacher at 3 PM.'（午後3時に先生に会うことになっている）
- Softening Refusals: Speakers often use this pattern for their own personal schedules when declining invitations. By framing the plan as an external, unchangeable schedule, it softens the refusal. For example, 'I'm supposed to meet a friend that day, so...'（その日は友達と会うことになっていまして…）.
- Official vs. Reality: It is often used to describe what is 'on paper,' 'supposed to happen,' or an 'official story/pretense' (建前), even if the reality is known to be different. For example, 'He is officially supposed to be off sick, but he is actually traveling.'（彼は病気で休むということになっているが、実は旅行に行っている）.
- Negative Rules: To express that you are 'supposed to not do something' (a prohibition), the negative form must attach to the verb (〜ないことになっている). Note that while 〜ことになっていない is grammatically valid, it has a different meaning: 'It is not a rule that...' or 'It hasn't been decided that...'.
- Past Plans/Rules: The past tense form ことになっていた is often used for plans or rules that were supposed to happen but ultimately fell through or changed. 'I was supposed to go to Tokyo, but...'（東京に行くことになっていたが…）
- Permission: When combined with the permission form 〜てもいい, as in 〜てもいいことになっている, it expresses that a rule allows something. 'It is a rule that you may use a dictionary during the exam.'（試験中に辞書を使ってもいいことになっている）
Because it describes an external arrangement, using it for personal habits can make it sound like you are being forced to do them by someone else. For personal habits or decisions you made yourself, use ことにしている instead. Note that while はず also translates to 'supposed to,' はず expresses a logical expectation by the speaker, whereas ことになっている states an objective rule, schedule, or established arrangement.
Note: In casual spoken Japanese, the い is often dropped, resulting in 〜ことになってる (e.g., 'I am supposed to meet my teacher at 3 PM.'（午後3時に先生に会うことになってる）). Conversely, in highly formal, written contexts like official documents, legal contracts, or news broadcasts, you may see the variant こととなっている.
Examples (4)
- 日本では、車は左側を走ることになっています。
In Japan, it is the rule that cars drive on the left side.
Word by Word: In Japan, cars left side (object) run thing (particle) has become.
This describes a legal requirement or established rule of the country.
- 明日の朝、９時に駅で待ち合わせることになっている。
We are supposed to meet at the station at 9:00 tomorrow morning.
Word by Word: Tomorrow morning, 9 o'clock at station at meet up thing has become.
This refers to a pre-arranged schedule or appointment made with another person.
- この部屋では、タバコを吸わないことになっています。
It is the rule not to smoke in this room.
Word by Word: This room in, tobacco (object) not smoke thing has become.
The negative form (ない form + ことになっている) is used to express prohibitions or rules about what not to do.
- ６０点以上が合格ということになっている。
It is established that 60 points or more is a passing grade.
Word by Word: 60 points or more (subject) pass that thing has become.
Using という before the pattern helps state a formal definition or criteria.
Common Mistakes
Using it for personal willpower or self-imposed habits.
私は毎日、３時間勉強することになっています。私は毎日、３時間勉強することにしています。If you use ことになっている, it sounds like a teacher or parent forced the rule on you. For personal choices or habits, use ことにしている.
Using the past tense for a rule that is still in effect.
ここでは靴を脱ぐことになった。ここでは靴を脱ぐことになっている。ことになった means the decision was just made. To describe the rule as it exists now, you must use the 〜ている form.
How It Connects
Learn This First
To understand 'koto ni natte iru', you need to know how to modify nouns with verbs, understand the verb 'naru' (to become), and be familiar with the 'te-iru' form which indicates a continuing state or result.
- ているProgressive/resultative
The pattern uses the resultative/progressive form of the verb 'naru' (to become) to express a state that has been established.
Level 2 - Noun Modification
The pattern involves modifying the noun 'koto' with a verb phrase to create the 'rule' or 'arrangement' being described.
Level 1 - なるTo Become
The core of the expression is the verb 'naru', indicating that a situation has 'become' or been set as a rule.
Level 1
Related Patterns
- ことにしているMake a Habit of
While ことになっている is for external rules, ことにしている is for personal habits and self-imposed rules.
Level 2 - ことになるIt's Been Decided
This focuses on the moment a decision is reached or an outcome is determined, rather than the ongoing state of the rule.
Level 3 - はずShould Be/supposed to
Both can mean 'supposed to,' but はず is based on the speaker's logical expectation, while ことになっている is based on an actual arrangement or rule.
Level 2 - 予定Plan/schedule
Used specifically for plans and schedules, whereas ことになっている covers rules and customs as well.
Level 2 - ものだUsed To/should (General)
Used for general social expectations or 'common sense' rules, rather than specific appointments or legal regulations.
Level 3
Words in This Pattern
Practice ことになっている in Bubblegum
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