「決める」 vs. 「決まる」: The JLPT N3 Difference Learners Often Get Wrong

Introduction

「決める」 and 「決まる」 are two verbs that JLPT N3 learners often confuse.

Both are related to the idea of “deciding” or “being decided,” so at first they can seem almost interchangeable.

Compare these two sentences:

「旅行の日を決めました。」
I decided the date of the trip.

「旅行の日が決まりました。」
The date of the trip has been decided.

Both sentences are about a trip date becoming fixed. However, they look at the situation from different perspectives.

The key question is:

Is someone actively making the decision?

Or are we focusing on the fact that something has now been decided?

This difference is small but extremely important. Because the meanings are so close, using the wrong verb often creates a sentence that is understandable but does not sound natural in Japanese.

Let’s start with some mistakes that Japanese learners commonly make.

Common Mistakes

Consider this sentence:

「来週の会議の日を決まりました。」
The date of next week’s meeting was decided.

The intended meaning is clear, but 「日を決まりました」 is not grammatically natural.

Here is another common example:

「私は大学を卒業したら日本へ留学すると決まりました。」
I decided that I would study abroad in Japan after graduating from university.

Again, the listener can probably understand what the speaker means.

However, if the speaker personally made the decision to study in Japan, 「決まりました」 is not the natural choice.

The problem comes from confusing the roles of 「決める」 and 「決まる」.

Why Do These Sentences Sound Unnatural?

The main difference is whether we focus on the person making a decision or on the result becoming fixed.

「決める」 (kimeru / to decide) is used when a person or group actively chooses something or makes a decision.

In other words, it naturally answers the question:

「誰が決めたのか。」
Who decided it?

For example:

「私は旅行の日を決めました。」
I decided the date of the trip.

Here, 「私」 is the person making the decision.

By contrast, 「決まる」 (kimaru / to be decided, to become fixed) focuses on the thing that becomes decided.

It naturally answers the question:

「何が決まったのか。」
What was decided?

For example:

「旅行の日が決まりました。」
The date of the trip has been decided.

In this sentence, who actually made the decision is not important. The important information is that the date is now fixed.

This is also why the particles are different.

「会議の日を決める」
to decide the meeting date

「会議の日が決まる」
the meeting date is decided

A useful pattern to remember is:

• 人が何かを決める

• Someone decides something.

• 何かが決まる

• Something is decided or becomes fixed.

Natural Ways to Say It

Let’s correct the earlier examples.

Unnatural:

「来週の会議の日を決まりました。」
The date of next week’s meeting was decided.

Natural:

「来週の会議の日を決めました。」
We decided the date of next week’s meeting.

Here, someone actively chose the date, so 「決める」 is appropriate.

We can also say:

「来週の会議の日が決まりました。」
The date of next week’s meeting has been decided.

This version focuses not on who chose the date, but on the result: the date is now fixed.

Now consider the second example.

Unnatural:

「私は大学を卒業したら日本へ留学すると決まりました。」
I decided that I would study abroad in Japan after graduating.

Natural:

「私は大学を卒業したら日本へ留学すると決めました。」
I decided to study abroad in Japan after graduating.

The speaker personally made this choice, so 「決める」 is natural.

However, this sentence is perfectly natural:

「来年、日本へ留学することが決まりました。」
It has been decided that I will study abroad in Japan next year.

Here, the focus is on the fact that the plan has officially been settled.

The event may be similar, but the speaker’s perspective is different.

The Basic Difference Between 「決める」 and 「決まる」

「決める」 (kimeru / to decide)

Use 「決める」 when someone actively chooses something, reaches a decision, or establishes a plan or rule.

A basic pattern is:

「人が何かを決める。」
A person decides something.

For example:

「私は旅行の日を決めました。」
I decided the date of the trip.

「みんなで店を決めましょう。」
Let’s decide on a restaurant together.

「今年の目標を決めました。」
I decided on my goals for this year.

The important idea is that someone is making a choice or judgment.

「決まる」 (kimaru / to be decided, to become fixed)

Use 「決まる」 when a schedule, plan, rule, result, or other matter becomes fixed or settled.

A basic pattern is:

「何かが決まる。」
Something is decided.

For example:

「旅行の日が決まりました。」
The date of the trip has been decided.

「会議の場所が決まりました。」
The location of the meeting has been decided.

「新しいルールが決まりました。」
The new rules have been decided.

The important point is not who made the decision, but the result that something is now settled.

A simple way to remember the difference is:

• 「決める」 = focus on the person or action making the decision
• 「決まる」 = focus on the result that something has been decided

Get a Feel for the Difference Through Examples

Example 1

「今夜、何を食べるか決めましたか。」
Have you decided what to eat tonight?

The listener is expected to choose what to eat.

Because a person is actively making a choice, 「決める」 is natural.

Example 2

「今日の夕食はカレーに決まりました。」
It has been decided that tonight’s dinner will be curry.

Here, the important point is the result: curry is now the chosen dinner.

Who made that decision is not important, so 「決まる」 is natural.

Example 3

「旅行の日程は家族で相談して決めました。」
We discussed it as a family and decided the travel schedule.

The family discussed the options and actively made a decision.

That is why 「決める」 is used.

Example 4

「旅行の日程がやっと決まりました。」
The travel schedule has finally been decided.

The sentence focuses on the fact that the schedule is finally settled.

Therefore, 「決まる」 is the natural choice.

Example 5

「私は毎朝30分、日本語を勉強すると決めています。」
I have decided to study Japanese for 30 minutes every morning.

This is a personal rule or decision made by the speaker.

Because it expresses personal intention, 「決める」 is appropriate.

Example 6

「来月から大阪支店で働くことが決まりました。」
It has been decided that I will work at the Osaka branch starting next month.

This sounds like an official arrangement, perhaps made by a company.

The sentence focuses on the confirmed result rather than the speaker personally choosing Osaka, so 「決まる」 is natural.

Example 7

「次のリーダーを誰にするか、今日中に決めなければなりません。」
We have to decide who the next leader will be by the end of today.

Someone must evaluate the candidates and make a choice.

Therefore, 「決める」 is used.

Example 8

「次のリーダーが田中さんに決まりました。」
Tanaka has been chosen as the next leader.

The selection process is finished, and Tanaka is now officially the leader.

The sentence focuses on the result, so 「決まる」 is natural.

Interestingly, both verbs can sometimes describe the same event from different perspectives.

「会社が新しい社長を決めました。」
The company chose the new president.

「新しい社長が決まりました。」
The new president has been chosen.

The first sentence focuses on the company’s action.

The second focuses on the result.

Understanding this difference in perspective is the key to mastering these two verbs.

How JLPT Questions Try to Trick You

Pairs like 「決める」 and 「決まる」 frequently appear in JLPT vocabulary and grammar questions because their meanings are closely related.

The wrong answer often looks very tempting.

For example:

「来月の試験の日が（　　　）。」
The date of next month’s exam has ______.

Suppose the choices include:

「決めました」
decided

「決まりました」
was decided

If you only think about the general meaning of “decide,” both may seem possible.

But look carefully at the particle:

「試験の日が」

The natural sentence is:

「来月の試験の日が決まりました。」
The date of next month’s exam has been decided.

Now compare:

「先生が試験の日を（　　　）。」
The teacher ______ the date of the exam.

Here the natural answer is:

「先生が試験の日を決めました。」
The teacher decided the date of the exam.

The particles give you a strong clue:

• 「人が＋何かを＋決める」

• Someone decides something.

• 「何かが＋決まる」

• Something is decided.

However, particles are not the only clue.

Compare:

「私は来年、日本へ行くことに決めました。」
I decided to go to Japan next year.

This expresses the speaker’s own decision.

Now compare:

「私は来年、日本へ行くことが決まりました。」
It has been decided that I will go to Japan next year.

This sounds more like the plan has been officially arranged or confirmed.

In JLPT questions, the wrong choice is often not completely unrelated in meaning. It is often a word that feels almost correct.

That is why you should not study vocabulary only through translations.

Ask yourself:

「誰が決めるのか。」
Who is making the decision?

「何が決まるのか。」
What is becoming fixed?

Is the sentence focusing on someone’s intention and action?

Or is it focusing on the result?

These questions will help you avoid many common JLPT traps.

Summary

「決める」 and 「決まる」 both relate to decisions, but they describe the situation from different perspectives.

「決める」 (kimeru / to decide) focuses on a person actively making a choice.

「決まる」 (kimaru / to be decided) focuses on something becoming settled or fixed.

Remember these two patterns:

• 「人が何かを決める。」

• Someone decides something.

• 「何かが決まる。」

• Something is decided.

For example:

「私たちは会議の日を決めました。」
We decided the date of the meeting.

「会議の日が決まりました。」
The date of the meeting has been decided.

At JLPT N3 and N2, being able to recognize these small differences is extremely important. Many questions are designed so that two choices look almost correct, but only one fits the grammar and context naturally.

RJT (Rapid Japanese Training) helps you build this skill by practicing Japanese in real JLPT-style questions rather than simply memorizing translations.

If you often understand the general meaning but still get stuck between the final two choices, practice identifying why one expression fits the sentence better than the other.

https://rapid-jt.com/