JLPT N4 Grammar – The difference between “〜ようにする” and “〜ことにする”

Table of Contents

1. The difference between “〜ようにする” and “〜ことにする”
2. 〜ようにする
3. 〜ことにする
4. Let’s Compare
5. Summary
6. Quiz
7. Similar Articles
8. Comments

Q: Can you explain how to use “〜ようにします” and “〜ことにします”?

A: The difference between “〜ようにする” and “〜ことにする” lies in whether the speaker is making a habitual effort or expressing something they have decided by their own will.
Let’s take a closer look.

〜ようにする (JLPT N4)

[Meaning]
Indicates something the speaker tries to do as a habit

[Rules]　
[V] Verb dictionary form + ようにする
[V] Verb ない form + ようにする

[Examples]
これから朝あさ5時じに起おきるようにします。
I will try to wake up at 5 AM from now on.

チョコレートのような甘あまいものは食たべないようにしています。
I try not to eat sweet things like chocolate.
⇒ “〜ようにしている” expresses a habit that is currently continuing.

健康けんこうのために、エレベーターではなく階段かいだんを使つかうようにしています。
I try to use the stairs instead of the elevator for my health.

When talking about another person’s habits or efforts, you can use “〜ようだ” to describe what it seems like, or “〜そうだ” to report information you have heard.

[Examples]
母はははダイエットのために、あまいものを食たべないようにしているようです。
My mother seems to be avoiding sweets in her diet.

木村きむらさんは朝あさ早はやく出勤しゅっきんするようにしているそうです。
I heard that Mr. Kimura tries to go to work early in the morning.

You can also use this expression when asking someone to make something a habit.

[Examples]
学校がっこうのルールは守まもるようにしましょう。
Let’s make sure to follow the school rules.

会社かいしゃを休やすむときは、メールで連絡れんらくするようにしてください。
Please notify us by email if you are absent from work.

〜ことにする (JLPT N4)

[Meaning]
Indicates something the speaker has decided based on their own judgment or intention

[Rules]　
[V] Verb Dictionary form + ことにする
[V] Verb ない form + ことにする

[Examples]
今日きょうは疲つかれているので、早はやく寝ねることにします。

I have decided to go to bed early today because I am tired.

これから朝あさ5時じに起おきることにしました。
I have decided to start waking up at 5 AM from now on.

健康けんこうのためにタバコをやめることにしました。
I decided to quit smoking for my health.

When talking about another person’s decision, you can use “〜ようだ” to describe what it seems like, or “〜そうだ” to report information you have heard, just as with “〜ようにする”.

[Examples] 　
トムさんは国くにへ帰かえることにしたようです。
Tom seems to have decided to return to his home country.

社長しゃちょうは引退いんたいすることにしたそうです。
The president has decided to retire.

[Cannot be used to give instructions]

“〜ことにする” expresses a decision made by the speaker, so it cannot be used when asking someone else to do something.

[Examples] 　
〇 先生せんせいに怒おこられてわたしは学校がっこうのルールを守まもることにしました。
After being scolded by the teacher, I decided to follow the school rules.
⇒ This expresses the speaker’s decision.

×（先生せんせいが生徒せいとに）学校がっこうのルールを守まもることにしましょう。
(Teacher to student) Let’s follow the school rules.

In this case, it should be expressed like this:

学校がっこうのルールは守まもるようにしましょう。
Let’s make sure to follow the school rules.

Let’s Compare

Even when the content is the same, the nuance changes depending on whether you use “〜ようにする” or “〜ことにする”.

[Examples]
これから朝あさ5時じに起おきるようにします。
I will start waking up at 5 AM from now on.
⇒ This expresses an effort to make something a habit.
　　　　　　　　　　　
これから朝あさ5時じにことにします。
I have decided to start waking up at 5 AM from now on.
⇒ This expresses a decision made by the speaker’s own will.

In this way, “〜ようにする” expresses habitual effort, while “〜ことにする” expresses a decision based on the speaker’s intention or judgment.

[Major life decisions]

When talking about major decisions in life—such as education, employment, or marriage—“〜ことにする” is usually used.

[Examples]
中国ちゅうごく語ごの勉強べんきょうのために、北京ぺきんの大学だいがくへ留学りゅうがくすることにしました。
I have decided to study abroad at a university in Beijing to learn Chinese.

3年ねん交際こうさいしている彼かれと結婚けっこんすることにしました。
I have decided to marry my boyfriend after dating for three years.

Summary

[〜ようにする]

• Indicates that the speaker is consciously making an effort to continue an action as a habit.
• It carries the nuance of “trying to make something a regular practice from now on.”
• It is often used when talking about daily habits or self-management.
• The form “〜ようにしています” is also commonly used to describe a habit that is currently continuing.

[〜ことにする]

• Indicates something the speaker has decided to do (or not do) based on their own intention or judgment.
• It is used to show a decision that the speaker has reached after thinking about it.
• It is often used when talking about relatively important decisions, such as education, employment, moving, or marriage.
• It cannot be used when asking someone else to take an action.

Quiz

Read the following sentence and choose the expression that fits the context from the options provided in the parentheses.

Click on the question to check the answer.