GrammarJLPT N5
→ it is decided that
It has been decided that / It turns out that
JLPT N5Fixed phraseNeutral
〜ことになる expresses a decision, arrangement, or outcome that has come about through external circumstances, group consensus, or natural consequence rather than through the speaker's own personal will. This is a crucial distinction from 〜ことにする, which indicates that the speaker actively made the decision themselves. With 〜ことになる, the focus is on the result or conclusion as something that "came to be" — the speaker presents the outcome as if it happened naturally or was determined by others. It is commonly used when announcing decisions made by companies, schools, or other organizations, or when describing a logical consequence of a situation. The grammar point is neutral in register and appears frequently in both spoken and written Japanese. When used in the past tense as 〜ことになった, it typically reports a decision that has already been finalized. It can also express that something logically results in or amounts to a certain conclusion.
Functions
#1 Announcing a decision made by others or external circumstances
Structure
Verb (dictionary form / ない-form) + ことになる / ことになった
来月、大阪に引っ越すことになりました。らいげつ、 おおさか に ひっこす こと に なりました。
Here ことになりました presents the move to Osaka as a decision that came about due to external factors — perhaps a job transfer or family circumstances — rather than purely the speaker's own choice. By using ことになる instead of ことにする, the speaker downplays their personal agency and presents the outcome as something that was decided or arranged, which is a very common and natural way to announce life changes in Japanese.It has been decided that I will move to Osaka next month.
Structures
- Verb (dictionary form)
- Verb (dictionary form) + ことになる
- Verb (ない-form)
- Verb (ない-form) + ことになる
Common mistakes
The most common mistake is confusing 〜ことになる with 〜ことにする. Remember that 〜ことになる presents the decision as coming from outside the speaker or as a natural outcome, while 〜ことにする emphasizes the speaker's own deliberate choice. Another frequent error is using 〜ことになる with adjectives or nouns directly; it attaches to verb forms, so learners should ensure they use the correct verb form before こと. Some learners also confuse 〜ことになる with 〜ようになる, which describes a gradual change in ability or habit over time, not a single decision or outcome. Finally, forgetting to use the past tense 〜ことになった when reporting a decision that has already been made is a common oversight — the non-past 〜ことになる sounds like the outcome is still pending or is a general logical consequence.
Related
〜ことにする〜ようになる〜ことになっている〜ということだ〜ことだ