ことにする (Koto Ni Suru)

What Does “Koto ni Suru” Mean?

The phrase “koto ni suru” translates roughly to “to decide to do…” or “to make it a plan to…” depending on the context.

It is used when you want to express a decision or a plan that you make for yourself. This is more personal than “koto ni naru,” as it implies that you are the one making the choice, unlike “koto ni naru”, where external circumstances often play a role.

Structure of “Koto Ni Suru”

“Koto ni suru” is made up of three main parts:

  • こと (koto): This is a noun that refers to an event, situation, or action. It’s often used to turn verbs into a noun, making the structure more abstract or formal.
  • に (ni): This particle indicates direction, change, or the result of an action.
  • する (suru): This verb means “to do,” and it indicates that you are actively making the decision to do something or taking an action.

When combined, ことにする (koto ni suru) can be used to convey that you are actively deciding or choosing to do something.

How to Use “Koto Ni Suru” in a Sentence

The general structure of “koto ni suru” is as follows:

<Action/Decision/Plan> + ことにする

For example:

勉強することにする
(Benkyou suru koto ni suru)
"I’ll decide to study."

仕事を辞めることにする
(Shigoto o yameru koto ni suru)
"I’ll decide to quit my job."-

When to Use “Koto Ni Suru”

Making Personal Decisions

“Koto ni suru” is often used when you make a personal decision or resolve to do something. This expression conveys your own agency in deciding on a particular course of action.

Example:

今日からダイエットをすることにする。
(Kyou kara daietto o suru koto ni suru.)
"I decide to start dieting from today."

Making a Plan or Arrangement

It can also be used when you are making a plan or arrangement, often in situations where you are taking control of the decision yourself.

Example:

来週、友達と映画を観に行くことにした。
(Raishuu, tomodachi to eiga o mi ni iku koto ni shita.)
"I decided to go see a movie with my friend next week."

Indicating an Intention to Do Something

“Koto ni suru” can express an intention to do something, suggesting that it’s a conscious decision you’ve made, either for the present or future.

Example:

この本を読むことにする。
(Kono hon o yomu koto ni suru.)
"I’ll decide to read this book."