to make something ~ (くする) – Japanese Grammar くする (ku suru)

Q: What JLPT level is くする?

JLPT N4 — Upper-Beginner · Forming complex sentences

Q: How do you use くする in a sentence?

Attach くする to the appropriate verb or noun form. To make something ~

Q: Is くする formal or casual Japanese?

くする can be used in both casual conversation and polite speech depending on context.

くする

N4 GRAMMAR ⏱ 0s study 📖 0 today

ku suru

to make something ~

ところ tokoro それでも sore demo さ sa と to ことができる koto ga dekiru し shi かしら ka shira ておく te oku てみる te miru はずだ hazu da ように / ような you ni / you na のに noni がする ga suru でも demo と言われている to iwarete iru とか～とか toka~toka って tte みたいだ mitai da らしい rashii やっと yatto ところ tokoro それでも sore demo さ sa と to ことができる koto ga dekiru し shi かしら ka shira ておく te oku てみる te miru はずだ hazu da ように / ような you ni / you na のに noni がする ga suru でも demo と言われている to iwarete iru とか～とか toka~toka って tte みたいだ mitai da らしい rashii やっと yatto

🃏 Flashcard

くする

ku suru

Tap to reveal usage

to make something ~

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📊 Pattern Stats

JLPT Level N4

Upper-Beginner · Forming complex sentences

Reading ku suru

Post ID 50720

Patterns today 0

0 / 10 daily goal

📝 Usage Notes

to make something ~

📖 How to use it

This pattern turns an adjective into a verb meaning 'to make something [adjective]'.

Attaches to Attach to the い-stem of an い-adjective (the form without the final い). For example, 高い (たかい) becomes 高く (たかく), then add する.

This pattern is used when someone changes the state of something, making it have the quality described by the adjective. It is like saying 'make it cheaper', 'make it cleaner', etc. The adjective is changed to its く form (the adverbial form), and then する is added. This is a very common and natural way to express 'to make something ~' in Japanese.

You can use this with many い-adjectives, such as 安い (cheap), 広い (spacious), 明るい (bright). The object is marked with を. For example, '音楽を大きくする' means 'to make the music loud(er)'. The pattern is also used with な-adjectives, but in that case you use に instead of く, as in 静かにする. But this entry focuses on い-adjectives with く.

A practical note: when you want to say 'make it a certain way' in a general sense, you can use this pattern with adjectives. For instance, when adjusting volume, temperature, or cleanliness, this is the natural expression.

テレビの音を小さくしてください。

Terebi no oto o chiisaku shite kudasai.

Please make the TV volume lower.

部屋をきれいにする時間がありません。

Heya o kirei ni suru jikan ga arimasen.

I don't have time to clean the room.

この写真をもっと大きくしたいです。

Kono shashin o motto ookiku shitai desu.

I want to make this photo bigger.

Not くなるくなる means 'to become ~' and describes a natural change without a direct actor. くする means 'to make something ~' and implies someone or something causes the change. For example, 部屋が明るくなる means 'the room becomes bright' (naturally), while 部屋を明るくする means 'I make the room bright'.

Register This pattern is neutral and used in both speaking and writing. It is standard Japanese at all levels of formality.

🎯 Quick Quiz

What does this grammar pattern mean or do?

くする

📚 How to Master This Pattern

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Say It Aloud

Press Hear it and repeat くする three times. Feel the rhythm — grammar patterns have a natural flow.

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Flip Before Reading

Always try to recall the usage before flipping the card. Struggle = learning. Every failed recall makes the next one stick harder.

✍️

Write Two Sentences

Compose two original sentences using くする. One about yourself, one about something you see right now.

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Spaced Review

Save this pattern and revisit at 10 min, 1 day, 3 days. Production (writing) beats recognition for grammar.

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❓ Frequently Asked Questions

What does the grammar pattern くする mean? ▼

To make something ~

What JLPT level is くする? ▼

Nihoner currently groups this pattern under JLPT N4 — Upper-Beginner · Forming complex sentences. Use the level label as study guidance rather than a prediction of what will appear on an exam.

How do you use くする in a sentence? ▼

Attach くする (ku suru) to the appropriate verb or noun form as described in the usage notes. Then try writing two original sentences — one about yourself and one about something around you.

Is くする formal or casual Japanese? ▼

くする is used in both casual and polite contexts. It appears frequently in everyday conversation, textbooks, and simple written materials.

How can I remember くする long-term? ▼

Use the flashcard on this page for active recall — see the pattern, reconstruct the usage from memory, then flip. Follow with the 4-choice quiz to distinguish it from similar patterns. Review later the same day and again over the following days. Writing original sentences can help you practise using the pattern in context.