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
Short (Plain) form + ので
Meaning: “because / since / so”
To express “because” using ので, follow these steps:
1. Conjugate the verb, adjective, or noun in its short (plain) form (either present or past tense).
2. 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 express “because,” ので is generally considered more polite and formal.
- から is used in spoken language, and is used when describing the reason/cause of something in a subjective way.
- ので is used in both spoken and written language. It is used when describing the reason/cause in an objective way.
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: Bought that game? – あのゲーム買った？
B: Nah, no money so… – いや、お金がないから…
In this situation, if B said お金がないので (Okane ga nai node), it would sound unnaturally polite and weird for friends talking casually.
4. Conjugation Reminders
| Type | ので phrase |
|---|---|
| Verb (present) | 食べる → 食べるので |
| Verb (past) | 行った → 行ったので |
| い-adjective | たのしい → たのしいので |
| な-adjective | げんきな → げんきなので |
| Noun | 先生 → 先生なので |
💡 Don’t forget the な before ので with nouns & な-adjectives!
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。 |
6. FAQ – Frequently Asked Questions
- QCan I start a sentence with ～ので?
- A
Yes, and it’s common in formal contexts. Example: 雪が降っているので、 今日は出かけません。= Because it’s snowing, I won’t go out today.
- QCan I use ～ので in casual conversation?
- A
Yes, but it feels more 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.
Always say: 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 in certain contexts, it’s much more common and standard to maintain politeness: [Plain Form Reason] + ので + [Polite Main Clause]. Ex: 「時間がないので、失礼します。」 (Jikan ga nai node, shitsurei shimasu. – Since I don’t have time, please excuse me.)
7. 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!
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