How do I use the grammar point koto ni suru for decisions?

What Does ことにする (koto ni suru) Mean?

The phrase ことにする is used in Japanese to indicate that someone has made a decision or has chosen to do something. It is typically translated as “decide to do” or “make it a rule to do” in English. This grammar point is a powerful tool for expressing your will or determination regarding future actions.

How to Form ことにする (koto ni suru)

To use koto ni suru, simply attach it to the plain (dictionary) form of a verb. Here’s the basic structure:

• Verb (plain form) + ことにする

For example:

• 勉強する (benkyou suru) – to study
• → 勉強することにする (benkyou suru koto ni suru) – decide to study

Examples of ことにする in Sentences

Let’s look at some practical examples of how koto ni suru is used to express decisions:

• 毎朝ジョギングすることにしました。
  I have decided to jog every morning.
• 来年日本に行くことにします。
  I will decide to go to Japan next year.
• 今日は外食しないことにする。
  I’ll decide not to eat out today.

Difference Between ことにする and ことにしている

While ことにする expresses a one-time decision, ことにしている means you have made a decision and are continuing the action as a habit or rule. For example:

• 毎日日本語を勉強することにしています。
  I make it a rule to study Japanese every day.

Common Mistakes to Avoid

When learning koto ni suru, beginners often confuse it with similar grammar points. Here are some tips to help you use it correctly:

• ことにする is for your own decisions, not for things decided by others or external factors.
• Do not use ことにする for spontaneous, in-the-moment actions. It implies some thought and intention.
• Remember to use the plain/dictionary verb form before ことにする.

When to Use ことにする

You should use koto ni suru when:

• You want to formally announce a decision (big or small).
• You are telling someone about a change in your routine or intention.
• You are expressing a resolution or promise to yourself or others.

Practice Using ことにする

To truly master this grammar point, try forming your own sentences about decisions you make in daily life. For example:

• 新しい趣味を始めることにします。
  I’ve decided to start a new hobby.
• 毎週土曜日は友達と会うことにする。
  I’ll decide to meet friends every Saturday.

Conclusion

Understanding how to use ことにする (koto ni suru) is vital for expressing personal decisions in Japanese. By practicing this grammar point, you will become more confident in sharing your intentions and resolutions. Keep practicing with real-life examples, and explore more Japanese grammar tips on the Talkpal – AI language learning blog to accelerate your Japanese journey!