ことにする

expression

to decide to

1. to decide to do something

Used after the plain form of a verb to express a decision made by the speaker. Implies a conscious, deliberate choice.

I decided to study abroad next year.

I'm going to go to bed early today.

For the sake of my health, I decided to walk every day.

As a result of the discussion, we decided to proceed with the new plan.

Verb dictionary form + ことにする: 行(い)くことにする (decide to go)
Verb ない form + ことにする: 行(い)かないことにする (decide not to go)
Past: ことにした (decided to)
ことにしている: to make it a rule to (毎朝(まいあさ)走(はし)ることにしている, I make a point of running every morning)

ことにする vs. ことになる: ことにする is an active decision by the speaker; ことになる indicates a decision made by others or circumstances.
ことにする vs. つもり: つもり expresses intention or plan; ことにする emphasizes the moment of decision.

The past form ことにした is more common than the non-past ことにする, since decisions are usually reported after being made.
After a past-tense verb it can also mean "to treat as, to pretend": 聞(き)かなかったことにする (I'll act as if I didn't hear that).

Related Words

general

Added 2026.2.12 15:50 · Revised 2026.10.19 23:26

10500/10986_kotonisuru