At a glance
～ことになる means "it has been decided that…" or "it turns out that…". It is used when a plan or arrangement was decided by other people or by circumstances, not simply by the speaker's own choice.
Verb (dictionary form / ない form) + ことになる
来月、大阪に引っ越すことになりました。 It's been decided that I'll move to Osaka next month.
How to form it
Put the verb in its plain form, then add ことになる:
| Attaches to | Example | Meaning |
|---|---|---|
| う-verb (dictionary form) | 行くことになる | it's decided that (I) will go |
| る-verb (dictionary form) | 始めることになる | it's decided that (I) will start |
| する verb | 勉強することになる | it's decided that (I) will study |
| 来る | 来ることになる | it's decided that (someone) will come |
| Verb ない form | 行かないことになる | it's decided that (I) won't go |
なる conjugates like this:
| Form | Polite | Casual |
|---|---|---|
| Present | ことになります | ことになる |
| Past | ことになりました | ことになった |
| Arrangement or rule | ことになっています | ことになっている |