How do I express decisions using koto ni suru?

What Does Koto ni Suru Mean?

Koto ni suru (ことにする) is a Japanese grammar pattern used to express a decision or determination made by the speaker. It can be translated as “to decide to (do something)” or “to choose to (do something)” in English. This structure is commonly used when you want to indicate that you have made up your mind about an action or a plan.

How to Form Koto ni Suru

The formation of koto ni suru is straightforward. Simply take the dictionary (plain) form of a verb and add koto ni suru:

• Verb (dictionary form) + ことにする

For example:

• 食べる (taberu – to eat) → 食べることにする (taberu koto ni suru) – “I will decide to eat.”
• 行く (iku – to go) → 行くことにする (iku koto ni suru) – “I will decide to go.”

Using Koto ni Suru in Different Tenses

Like many Japanese grammar structures, koto ni suru can be used in various tenses and forms to match the context of your sentence. Here are some examples:

• Present/future decision: 日本語を勉強することにします。 (Nihongo o benkyou suru koto ni shimasu.) – I will decide to study Japanese.
• Past decision: 日本に行くことにしました。 (Nihon ni iku koto ni shimashita.) – I decided to go to Japan.

Common Examples of Koto ni Suru

Here are a few practical examples to help you see how koto ni suru is used in daily conversation:

• 今日は外で食べることにします。 (Kyou wa soto de taberu koto ni shimasu.) – I’ve decided to eat outside today.
• 毎日運動することにしました。 (Mainichi undou suru koto ni shimashita.) – I’ve decided to exercise every day.
• 車を買わないことにしました。 (Kuruma o kawanai koto ni shimashita.) – I’ve decided not to buy a car.

Koto ni Suru vs. Koto ni Naru

It’s important to distinguish between koto ni suru and koto ni naru. While both can be translated as “to decide,” koto ni suru indicates a personal decision made by the speaker, whereas koto ni naru refers to a decision made by someone else or as a result of circumstances.

• 会社をやめることにしました。 (Kaisha o yameru koto ni shimashita.) – I decided to quit the company.
• 会社をやめることになりました。 (Kaisha o yameru koto ni narimashita.) – It has been decided (not necessarily by me) that I will quit the company.

When to Use Koto ni Suru

Use koto ni suru when you want to:

• Clearly state a decision you have made yourself.
• Share your intentions or plans with others.
• Talk about changes in your habits or routines.

It is especially useful in both formal and informal situations, making it a versatile tool for expressing your choices in Japanese.

Tips for Mastering Koto ni Suru

• Practice making sentences about your daily decisions using koto ni suru.
• Pay attention to context—use koto ni suru for your own decisions, and koto ni naru for decisions made by others or by circumstance.
• Try using it in conversation with language partners or in writing exercises on platforms like Talkpal for more natural practice.

Conclusion

Understanding how to express decisions in Japanese using koto ni suru is an important step for any learner. This grammar pattern allows you to communicate your intentions, plans, and choices clearly and naturally. By practicing with real-life examples and paying attention to the subtle differences between koto ni suru and similar expressions, you’ll find yourself speaking Japanese with more confidence and accuracy. For more language learning tips and practical grammar guides, be sure to explore other articles on the Talkpal AI language learning blog!