Processing keyword: い-Adjective く する-なる (i-Adjective kusuru-naru)

Japanese Grammar Point: い-Adjective く する-なる (i-Adjective kusuru-naru)

い-Adjective + くする・なる (i-Adjective + ku suru/naru)

1. Introduction

In Japanese, expressing changes in state or causing something to change is essential for everyday communication. The grammar structures 〜くなる and 〜くする are used with い-adjectives to indicate that something becomes a certain way or someone makes something a certain way.

---

2. Core Grammar Explanation

Meaning and Usage

• 〜くなる (ku naru): Indicates that something becomes a certain state naturally or over time.
• 〜くする (ku suru): Indicates that someone makes something change to a certain state.

Formation

To use these structures with い-adjectives, follow these steps:

1. Remove the final い from the い-adjective.
2. Add くなる or くする.

Formation Diagram

[い-Adjective] - い + くなる／くする

---

Examples of Formation

い-Adjective	Remove い	Add くなる／くする	Meaning
高い（たかい）	高**　**	高くなる／高くする	Become expensive / Make expensive
早い（はやい）	早**　**	早くなる／早くする	Become early / Make early
強い（つよい）	強**　**	強くなる／強くする	Become strong / Make strong

---

3. Comparative Analysis

• 〜くなる／くする is used with い-adjectives.
• 〜になる／にする is used with な-adjectives and nouns.

Example with な-adjective:

• 静かになる／静かにする (Shizuka ni naru / Shizuka ni suru)
  Become quiet / Make quiet

---

4. Examples in Context

Example Sentences

1. 天気が暖かくなりました。
   Tenki ga atatakaku narimashita.
   The weather has become warm.
2. 部屋を明るくします。
   Heya o akaruku shimasu.
   I will make the room bright.
3. 彼は以前より強くなった。
   Kare wa izen yori tsuyoku natta.
   He has become stronger than before.
4. 音楽で気持ちを穏やかにしました。
   Ongaku de kimochi o odayaka ni shimashita.
   I calmed my feelings with music.
5. 毎日運動すると健康になります。
   Mainichi undō suru to kenkō ni narimasu.
   If you exercise every day, you become healthy.

---

5. Cultural Notes

Cultural Relevance

In Japanese culture, expressing changes in state is common, reflecting an appreciation for gradual change and harmony. The use of 〜くなる and 〜くする aligns with this cultural aspect by describing natural transitions or intentional alterations.

Levels of Politeness

• Using ます form (e.g., なりました/します) adds politeness.
• Plain forms (e.g., なった/する) are casual and used among friends or in informal settings.

Idiomatic Expressions

• 元気になる (genki ni naru): To get well/recover.
• 上手になる (jōzu ni naru): To become skilled.

---

6. Common Mistakes and Tips

Error Analysis

• Incorrect: 高いなる (takai naru)
  • Error: Not changing い-adjective to く form.
  • Correction: 高くなる (takaku naru)

Learning Strategies

• Mnemonic Device: Think of く as a bridge connecting the adjective to なる/する.
• Practice Tip: Conjugate various い-adjectives into 〜くなる／くする forms to build familiarity.

---

7. Summary and Review

Key Takeaways

• 〜くなる is used to indicate that something becomes a certain way naturally.
• 〜くする is used when someone makes something become a certain way.
• Formation involves changing an い-adjective by replacing the final い with く.

Quick Recap Quiz

1. How do you say "to make something cheap" using 安い（やすい）?
   • Answer: 安くする (Yasuku suru)
2. What is the polite form of "became interesting" using 面白い（おもしろい）?
   • Answer: 面白くなりました (Omoshiroku narimashita)
3. Fill in the blank: 彼は日本語が _______ なりました。(He has gotten good at Japanese.)
   • Answer: 上手に (Jōzu ni)

---

By understanding and practicing this grammar point, you'll be able to express changes in states and causation effectively in Japanese!