A1 Collocation Neutral 2 min read

決定をする

kettei o suru

decide

Literally: Decision (to) do

In 15 Seconds

  • Used for making firm, official, or final decisions.
  • More formal and heavy than the common verb 'kimeru'.
  • Common in business, life milestones, and official contexts.

Meaning

This phrase means to reach a firm conclusion or finalize a choice. It is like saying 'I have made my decision' rather than just 'I am picking something.'

Key Examples

3 of 6
1

In a business meeting about a project

新しいプロジェクトの予算を決定しました。

We have decided on the budget for the new project.

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2

Choosing a wedding venue with a partner

ついに結婚式の会場を決定したよ!

We finally decided on the wedding venue!

<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4.318 6.318a4.5 4.5 0 000 6.364L12 20.364l7.682-7.682a4.5 4.5 0 00-6.364-6.364L12 7.636l-1.318-1.318a4.5 4.5 0 00-6.364 0z"/></svg>
3

Texting a friend about travel plans

旅行の日程、これで決定でいい?

Is it okay to finalize the trip dates with this?

<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M14.828 14.828a4 4 0 01-5.656 0M9 10h.01M15 10h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>
🌍

Cultural Background

Decisions are often made after long consultation. Decisions are often made by individuals quickly.

💡

Use sparingly

Don't use this with friends!

In 15 Seconds

  • Used for making firm, official, or final decisions.
  • More formal and heavy than the common verb 'kimeru'.
  • Common in business, life milestones, and official contexts.

What It Means

決定をする means making a firm, official decision. It feels much heavier than just choosing a flavor of ice cream. Think of it as reaching a final conclusion. You are not just thinking about it anymore. You are setting your choice in stone. It carries a sense of authority and finality. It is the moment the debate ends and action begins.

How To Use It

You take the noun 決定 (decision) and add the verb する (to do). You can keep the particle in the middle for emphasis. Or you can drop it to say 決定する for speed. Use the past tense 決定した when the choice is finished. If you want to be polite, use 決定しました. It is a very versatile structure for any serious situation.

When To Use It

Use this in business meetings when a project is approved. Use it for big life events like choosing a university. It is perfect for wedding planning or buying a house. It sounds professional, clear, and very decisive. If you tell your boss 決定しました, they know the matter is closed. It works well in formal emails and official announcements too. You will sound like someone who gets things done.

When NOT To Use It

Do not use it for tiny, daily things. Like choosing between a latte or a mocha. That sounds way too dramatic for a coffee shop. For small daily choices, use 決める instead. Using 決定をする for a sandwich choice might make your friends laugh. It is like calling a formal press conference for a snack. Keep it for the things that actually matter.

Cultural Background

In Japan, decisions often take a lot of time. People like to reach a consensus first. This process is called nemawashi. Once everyone finally agrees, the 決定 is made. It represents the final step of a long group process. It is about stability and group harmony. Making a 決定 means everyone is now moving in the same direction. It is a powerful moment in a Japanese company.

Common Variations

You will often hear 決定しました in the office. In casual talk, you might hear 決定だね which means 'It's a done deal!' If you want to be very polite, use 決定いたしました. There is also 最終決定, which means 'final decision.' It sounds very cool and definitive. You might see 決定事項 on a meeting agenda. That means 'items already decided.'

Usage Notes

This phrase sits in the neutral to formal register. It is most commonly found in business, journalism, and when discussing significant life milestones.

💡

Use sparingly

Don't use this with friends!

Examples

6
#1 In a business meeting about a project
<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 13.255A23.931 23.931 0 0112 15c-3.183 0-6.22-.62-9-1.745M16 6V4a2 2 0 00-2-2h-4a2 2 0 00-2 2v2m4 6h.01M5 20h14a2 2 0 002-2V8a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z"/></svg>

新しいプロジェクトの予算を決定しました。

We have decided on the budget for the new project.

Using 'kettei' shows the budget is now official and fixed.

#2 Choosing a wedding venue with a partner
<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4.318 6.318a4.5 4.5 0 000 6.364L12 20.364l7.682-7.682a4.5 4.5 0 00-6.364-6.364L12 7.636l-1.318-1.318a4.5 4.5 0 00-6.364 0z"/></svg>

ついに結婚式の会場を決定したよ!

We finally decided on the wedding venue!

The exclamation shows excitement over a big life choice.

#3 Texting a friend about travel plans
<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M14.828 14.828a4 4 0 01-5.656 0M9 10h.01M15 10h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>

旅行の日程、これで決定でいい?

Is it okay to finalize the trip dates with this?

A slightly more casual way to ask for a final 'yes'.

#4 A teacher announcing a school trip destination
<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 13.255A23.931 23.931 0 0112 15c-3.183 0-6.22-.62-9-1.745M16 6V4a2 2 0 00-2-2h-4a2 2 0 00-2 2v2m4 6h.01M5 20h14a2 2 0 002-2V8a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z"/></svg>

今年の修学旅行は京都に決定しました。

It has been decided that this year's school trip is to Kyoto.

Formal announcement style for a group.

#5 Joke among friends about a dinner choice
<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M14.828 14.828a4 4 0 01-5.656 0M9 10h.01M15 10h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>

今夜のメニューはラーメンに決定する!

I hereby decree that tonight's menu shall be ramen!

Using such a formal word for ramen adds a humorous, dramatic effect.

#6 Deciding on a new house
<svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M14.828 14.828a4 4 0 01-5.656 0M9 10h.01M15 10h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>

家族で話し合って、この家に決定しました。

After a family discussion, we decided on this house.

Shows the decision was made after consultation.

Test Yourself

Which is more appropriate for a business meeting?

会議で____。

✓ Correct! ✗ Not quite. Correct answer: 決定をする

The first is formal, the second is too casual.

🎉 Score: /1

Visual Learning Aids

Practice Bank

1 exercises
Which is more appropriate for a business meeting? Choose A1

会議で____。

✓ Correct! ✗ Not quite. Correct answer: 決定をする

The first is formal, the second is too casual.

🎉 Score: /1

Frequently Asked Questions

1 questions

No, it sounds too formal.

Related Phrases

🔗

決める

similar

To decide

🔗

決断を下す

specialized form

To make a hard resolution

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