How do you say "I’ll be good." in Japanese?

"I’ll be good." in Japanese is "いいこにするね". This phrase is commonly used in Japan.

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How to Say ‘I’ll be good.’ in Japanese

Q: How do you say "I’ll be good." in Japanese?

"I’ll be good." in Japanese is "いいこに するね". This phrase is commonly used in Japan.

Q: What does "いいこに するね" mean in English?

"いいこに するね" means "I’ll be good." in English. Usage tip: [いいこに するね] literally means “I’ll make myself a good child.” It is a natural childlike way to say “I’ll be good.”

いいこにするね

ii ko ni suru ne

[ee koh nee soo-roo neh]

💬 Usage Tip: [いいこにするね] literally means “I’ll make myself a good child.” It is a natural childlike way to say “I’ll be good.”

🇯🇵 In Japan: Adults may say this to children, and children may repeat it back. It has a cute, obedient tone often heard in family settings.

Phrase Breakdown

いい

[ee]

good; well-behaved

Describes someone as good or well-behaved.

Example

いいこにしていてね。

Be a good child, okay.

こ

[koh]

child

A casual hiragana form meaning child, often used in affectionate speech.

Example

いいこはだれかな。

Who is the good child?

に

[nee]

into; as

Marks what something becomes or what is chosen.

Example

いいこにするね。

I'll make them a good child / I'll keep them well-behaved, okay.

する

suru

[soo-roo]

to do; to make; to choose

Here it means to make or keep someone/something in a certain state.

Example

へやをきれいにする。

I make the room clean.

ね

[neh]

okay?; you know; soft ending

Adds a gentle, friendly tone to what the speaker is saying.

Example

いいこにするね。

I'll be a good child, okay.

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