Video
Let’s watch this short video for a quick overview.
Source: gokigen japanese official YouTube Channel
Introduction
You’ve probably already learned that から can be used to say “because” in Japanese. But did you know that there’s a softer, more polite way to say the same thing?
Meet 〜ので — another way to express “because,” often used in formal situations, explanations, and written language.
In this article, you’ll learn:
- How to use ～ので with verbs, adjectives, and nouns
- How it differs from 〜から
- How to sound more natural and polite in Japanese conversation
1. Grammar Pattern
Pattern: Short (Plain) form + ので
Meaning: “because / since / so”
To express “because” using ので, follow these steps:
- Conjugate the verb, adjective, or noun in its short [plain] form (either present or past tense).
- Add ので after the short form.
When using ので with な-adjectives & nouns in present tense, you have to add な before ので.
| Type | Example | Result |
|---|---|---|
| Verb | 帰る | 帰るので (because I’m going home) |
| い-adjective | 忙しい | 忙しいので (because I’m busy) |
| な-adjective | しずかな | しずかなので (because it’s quiet) |
| Noun | 学生 | 学生なので (because [they] are a student) |
2. Example Sentences
頭が痛いので、帰ってもいいですか。
I have a headache, so may I go home?
わたしはベジタリアンなので、肉を食べません。
Because I’m a vegetarian, I don’t eat meat.
今日は日曜日なので、銀行は休みです。
The bank is closed because today is Sunday.
雨が降っているので、出かけません。
Because it’s raining, I won’t go out.
3. How is ～ので Different from ～から?
While both ので and から mean “because,” they differ in tone and level of formality.
- から is more casual and is commonly used in everyday spoken language.
- It can sound more direct and expresses the speaker’s subjective reason.
- ので is generally more polite and formal.
- It is used in both spoken and written language, and it gives a softer, more objective impression.
Because of these differences:
- With friends, classmates, or family, から is far more common.
- With teachers, bosses, or people of higher status, ので often sounds more appropriate and natural.
Example Comparison:
- 時間がないから、行きません。= I’m not going because I don’t have time. (casual)
- 時間がないので、行きません。= Since I don’t have time, I won’t go. (polite)
Context: Two middle schoolers talking about a new game.
A: あのゲーム買った？ – Bought that game?
B: いや、お金がないから… – Nah, no money so…
Here, “お金がないので” would sound too polite and unnatural between friends.
In casual conversations like this, から is the default choice.
4. Conjugation Reminders
| Type | ので phrase |
|---|---|
| Verb (present) | 食べる → 食べるので |
| Verb (past) | 食べた → 食べたので |
| い-adjective (present) | たのしい → たのしいので |
| い-adjective (past) | たのしかった → たのしかったので |
| な-adjective (present) | げんき → げんきなので |
| な-adjective (past) | げんきだった → げんきだったので |
| Noun (present) | 先生 → 先生なので |
| Noun (past) | 先生だった → 先生だったので |
When using ので with な-adjectives & nouns in present tense, you have to add な before ので.
5. Practice Time!
Convert the following to 〜ので sentences:
| English | Japanese |
|---|---|
| I’m tired, so I’ll sleep early. | 疲れているので、早く寝ます。 |
| It’s nice weather, so I’ll do laundry. | いい天気なので、洗濯します。 |
| I caught a cold, so I stayed home. | 風邪をひいたので、家で休みました。 |
| I received a gift, so I’m happy. | プレゼントをもらったので、うれしいです。 |
| It’s Sunday, so I’m free. | 日曜日なので、ひまです。 |
FAQ – Frequently Asked Questions
- QCan I use ～ので in casual conversation?
- A
It feels overly polite. In very casual situations, ～から is more common.
- QWhat if I forget the な for な-adjectives or nouns?
- A
Your sentence may sound awkward or grammatically wrong.
In present tense, you have to add な before ので: しずかなので、がくせいなので
- QWhy do I need な before ので with な-adjectives and nouns (e.g., 学生なので)? Why not だ?
- A
This is a specific rule for connecting present affirmative な-adjectives and nouns to ので (and also to んです/の).
While the plain form ends in だ (e.g., 学生だ), this だ changes to な when followed directly by ので.
Think of な as the required linking form in this specific grammatical context. For い-adjectives (e.g., 忙しい) and verbs (e.g., 行く), you use their standard plain forms directly before ので (忙しいので, 行くので).
- QSince ので itself sounds polite, does the final sentence ending also need to be polite (ます/です)?
- A
Generally, yes. Because ので carries a polite and somewhat formal nuance, it naturally pairs best with a polite sentence ending (using ます/です).
While you might occasionally hear it followed by a plain form sentence ending, it’s much more common and standard to maintain the same politeness level.
The examples below are listed in order of formality, from most to least.
- 日本語はおもしろいので、日本語を勉強しています。
- 日本語はおもしろいから、日本語を勉強しています。
- 日本語はおもしろいから、日本語を勉強してる。
Conclusion
Now you can express polite reasons using:
✅ Short-form verbs, adjectives, and nouns + ので
✅ Polite, formal-sounding “because”
✅ Proper use of な with nouns and な-adjectives
🎯 Try this: Write 3 polite sentences using 〜ので to explain why you’re doing (or not doing) something!
Want to improve your Japanese with real conversations?
Our native Japanese instructors at gokigen japanese can help you perfect your pronunciation and learn real-life usage.
Whether you’re completely new to Japanese or looking to refine your skills, book a one-on-one session.
