Genki Grammar #134: Mastering -koto ni shiteiru

Introduction

Today, we will learn about -koto ni shiteiru, an important grammar structure that helps you express your habits or decisions. If you want to say, “I have made it a rule to do something,” this is the phrase you need.

What It Means

The structure -koto ni shiteiru means that you have made a personal decision or resolution and are following it regularly. It often describes good habits or rules you have set for yourself.

Example Explanation:

• 毎日11時までに寝ることにしています。 (Mainichi juuichi-ji made ni neru koto ni shiteimasu.)
  I make it a rule to go to bed by eleven every night.
• 絶対にお酒を飲まないことにしています。 (Zettai ni osake o nomanai koto ni shiteimasu.)
  I have made this firm decision not to drink and have strictly followed it.

When to Use It

Use -koto ni shiteiru when you want to talk about:

1. Habits or routines: Something you have decided to do regularly.
2. Personal rules: Decisions you have made to improve yourself or stick to a plan.

It’s different from just saying “I do” something because it includes the idea that you made the decision on purpose.

How to Form It

To create sentences with -koto ni shiteiru, follow this simple structure:

Verb (short, present form) + ことにしている (koto ni shiteiru)

Example Sentence Structure:

• 食べる (taberu) + ことにしている (koto ni shiteiru)
  → 食べることにしています (Taberu koto ni shiteimasu.)
  I make it a rule to eat healthy.

Examples

Here are more sentences to help you understand:

1. 毎日日本語を勉強することにしています。
   (Mainichi nihongo o benkyou suru koto ni shiteimasu.)
   I make it a rule to study Japanese every day.
2. 週に三回運動することにしています。
   (Shuu ni sankai undou suru koto ni shiteimasu.)
   I make it a rule to exercise three times a week.
3. 毎朝早く起きることにしています。
   (Maiasa hayaku okiru koto ni shiteimasu.)
   I make it a rule to wake up early every morning.

Notes

• If you are talking about a one-time decision, use -koto ni shita instead of -koto ni shiteiru (-koto ni shiteiru).
  • Example: 今日はテレビを見ないことにした。
    (Kyou wa terebi o minai koto ni shita.)
    I decided not to watch TV today.

Conclusion

Mastering -koto ni shiteiru will help you talk about your habits and personal rules in Japanese. Try using it to describe your daily routines and self-made rules!

Recommended Resources

To deepen your understanding of -koto ni shiteiru and similar grammar patterns, I recommend the book Japanese: A Comprehensive Grammar by Stefan Kaiser et al. This resource covers a wide range of essential grammar points, including expressions for habits and resolutions, with detailed explanations in English. It’s highly regarded for its clarity and practical examples, making it ideal for learners aiming to master Japanese grammar step by step.