Genki Grammar #123: Mastering Adjective + suru

Introduction

In Japanese, you can use the irregular verb する (suru) with adjectives to describe actions that “make” something change. This structure is perfect for expressing intentional actions, like making a room clean or simplifying a process. In this post, we’ll explore how to combine adjectives with suru to say “make something [adjective].”

What It Means

When you combine an adjective with する (suru), it means “to make something [adjective].” For example:

• 冷たくする (tsumetaku suru) – “to make something cold.”

This is different from saying なる (naru), which means “to become.” While なる describes a change that happens naturally, する shows a deliberate action to create that change.

When to Use It

Use Adjective + suru when:

1. You want to describe an intentional action to change something.
2. You want to make something more or less of a specific quality.

This pattern is used with both い-adjectives and な-adjectives.

How to Form It

1. For い-adjectives: Drop the final い and add くする.
   • Example: 冷たい (tsumetai) → 冷たくする (tsumetaku suru) – “to make cold.”
2. For な-adjectives: Add にする to the base form of the adjective.
   • Example: 簡単な (kantan na) → 簡単にする (kantan ni suru) – “to make simple.”

Examples

Here are some examples to help you understand how to use Adjective + suru in sentences.

1. この間の試験は難しすぎたので、次の試験はやさしくしてください
   (Kono aida no shiken wa muzukashisugita node, tsugi no shiken wa yasashiku shite kudasai)
   Please make the next exam easier, because the last one was too difficult.
   • Adjective: やさしい (yasashii) → やさしくする (yasashiku suru).
2. みんなで世界をよくしましょう
   (Minna de sekai o yoku shimashou)
   Let’s join our forces and make the world a better place.
   • Adjective: いい (ii) → よくする (yoku suru).
3. 部屋をきれいにしました
   (Heya o kirei ni shimashita)
   I cleaned the room. (lit., I made the room clean.)
   • Adjective: きれいな (kirei na) → きれいにする (kirei ni suru).
4. 静かにしてください
   (Shizuka ni shite kudasai)
   Please be quiet!
   • Adjective: 静かな (shizuka na) → 静かにする (shizuka ni suru).

Notes

• Difference Between する and なる:
  • する means “to make something [adjective]” (intentional).
    • Example: 部屋をきれいにしました (Heya o kirei ni shimashita) – I made the room clean.
  • なる means “to become [adjective]” (natural or unintentional).
    • Example: 部屋がきれいになりました (Heya ga kirei ni narimashita) – The room became clean.
• Idiomatic Use:
  The phrase 静かにする (shizuka ni suru) means “to make it quiet” but is often used as a command:
  • 静かにしてください (Shizuka ni shite kudasai) – Please be quiet!

Conclusion

The Adjective + suru structure is a powerful tool for describing deliberate actions to change things. By mastering this grammar point, you can express a variety of actions, from improving situations to making changes in your environment. Practice combining adjectives with する, and soon you’ll be able to describe intentional changes with ease.

Recommended Resources

For a deeper understanding of Adjective + suru, I recommend A Dictionary of Basic Japanese Grammar. This book explains the concept under the entry suru1, providing detailed explanations and examples of how suru can be used with adjectives to express intentional changes. If you want to explore this grammar point further and see more practical examples, this book is an excellent resource to enhance your Japanese skills.