N3Rules and Decisions

V-dictionary/V-nai + ことにしている

Q: Is "Confusing with 'koto ni natte iru' (public rules/customs)" correct?

No. The correct form is "Use 'koto ni shite iru' to express a personal habit or rule.". The key difference is that 'koto ni shite iru' emphasizes the speaker's ongoing effort or intention, while 'koto ni natte iru' implies a public or general rule.

Q: Is "Using the simple 'suru' instead of 'shite iru' for habits" correct?

No. The correct form is "Use 'shite iru' to express a habit or rule.". The simple 'suru' implies a one-time action, while 'shite iru' implies a repeated or ongoing action.

Q: Is "Mixing up with 'you ni shite iru' (trying to do, but slightly less firm)" correct?

No. The correct form is "Use 'you ni shite iru' to express a tentative or uncertain intention.". The key difference is that 'you ni shite iru' implies a tentative or uncertain intention, while 'ni shite iru' implies a firm decision or rule.

to make it a rule to

Definition

Meaning

The grammar pattern "V-dictionary/V-nai + にことにしている" is used to express a personal habit or a rule that the speaker has decided for themselves and continues to follow. This emphasizes the speaker's ongoing effort or intention. For example, "毎日寝る前に、30分本を読むことにしている" means 'I have decided to read a book for 30 minutes before going to bed every day.'

Structure

Formation Rules

Form	Pattern	Example
Dictionary form	V-dictionary + にことにしている	食べにしている (I have decided to eat)
Nai form	V-nai + にことにしている	食べないことにしている (I have decided not to eat)
Volitional form	V-ます + にことにしている	食べますことにしている (I have decided to eat)

Examples

Example Sentences

毎日寝る前に、30分本を読むことにしている。

Mainichi neru mae ni, 30-fun hon o yomu koto ni shite iru.

I have decided to read a book for 30 minutes before going to bed every day.

毎日 (every day), 寝る前に (before going to bed), 30分 (30 minutes), 本 (book), 読む (to read), にことにしている (have decided to)

太らないように、夜8時以降は何も食べないことにしている。

Ossanai yō ni, yoru 8-ji ijo wa nanimo tabenai koto ni shite iru.

I have decided not to eat anything after 8 pm to lose weight.

太らないように (to lose weight), 夜8時以降 (after 8 pm), 何も (nothing), 食べない (not to eat), にことにしている (have decided to)

環境のために、買い物には自分のバッグを使用することにしている。

Kankyō no tame ni, kaimono ni wa jibun no baggu o shiyō suru koto ni shite iru.

I have decided to use my own bag when shopping for the environment.

環境のために (for the environment), 買い物 (shopping), 自分のバッグ (own bag), 使用する (to use), にことにしている (have decided to)

Context

Usage Notes

This pattern is used to express a personal habit or a rule that the speaker has decided for themselves and continues to follow. It emphasizes the speaker's ongoing effort or intention. This pattern is often used in formal or written Japanese.

Watch out

Common Mistakes

Confusing with 'koto ni natte iru' (public rules/customs)

Use 'koto ni shite iru' to express a personal habit or rule.

The key difference is that 'koto ni shite iru' emphasizes the speaker's ongoing effort or intention, while 'koto ni natte iru' implies a public or general rule.

Using the simple 'suru' instead of 'shite iru' for habits

Use 'shite iru' to express a habit or rule.

The simple 'suru' implies a one-time action, while 'shite iru' implies a repeated or ongoing action.

Mixing up with 'you ni shite iru' (trying to do, but slightly less firm)

Use 'you ni shite iru' to express a tentative or uncertain intention.

The key difference is that 'you ni shite iru' implies a tentative or uncertain intention, while 'ni shite iru' implies a firm decision or rule.

Strategy

JLPT Exam Tips

Pay attention to the context and the speaker's intention when using this pattern. Make sure to use the correct form and pattern to express the speaker's ongoing effort or intention.

In context