If you want to sound more natural and expressive in Japanese conversations, one powerful grammar pattern you should know is 〜んです (also written as 〜のです in formal writing).

This structure helps you:

• Explain reasons
• Show emotions or background information
• Ask questions in a more natural, curious way

Let’s break down how it works and when to use it!

What Is 〜んです?

The phrase 〜んです is a shortened and more casual form of 〜のです. It adds nuance, emotion, or explanation to a sentence. You’ll hear it all the time in real-life conversations, especially when people are explaining why something happened or asking someone else for more information.

When to Use 〜んです

✅ To explain a reason (like “because…”)

Example:
今日きょうは行いけないんです。
(I can’t go today – because of something.)

This shows you’re giving a reason or background. Without んです, it sounds more blunt or robotic:

× 今日きょうは行いけません。 ← Just a plain statement

✅ To give background or feelings

Example:
頭あたまが痛いたいんです。
(It’s that I have a headache / I’m not feeling well.)

This version sounds softer and more empathetic, especially if you’re talking to a friend or teacher.

✅ To ask naturally for explanations or more info

Example:
どうしたんですか？
(What happened?)

Compare that with:
× 何なにがありましたか？ ← Formal and distant

How to Use 〜んです in Different Forms

What’s the Difference Between 〜んです and Just です／ます?

A common question for learners is:
“What’s the difference between saying something like『行いきます』and『行いくんです』?”

Great question! Let’s compare.

🔹 Simple です／ます = Just telling a fact

明日あしたは行いきません。
(I won’t go tomorrow.)
→ A plain and polite statement, but no explanation.

🔸 ～んです = Giving a reason or emotional background

明日あしたは行いけないんです。
(It’s that I can’t go tomorrow – giving a reason or excuse)
→ More natural when someone is expecting a reason.

Another Example

Simple Statement:
今いま、忙いそがしいです。
→ I’m busy now. (Just stating a fact)

Explanatory Statement:
今いま、忙いそがしいんです。
→ I’m busy now (giving a reason for not replying, for example)

When to Use Each

Examples in Real Life Conversations

A：遅おそかったね。どうしたの？
B：道みちがこんでいたんです。
(A: You were late. What happened?)
(B: It’s that there was traffic.)

A：明日あした、来こられますか？
B：ちょっと用事ようじがあるんです。
(A: Can you come tomorrow?)
(B: It’s that I have something to do.)

A：最近さいきん、元気げんきがないね。
B：実じつはちょっと悩なやみがあるんです。
(A: You haven’t seemed yourself lately.)
(B: Actually, I have something on my mind.)

Practice Time!

Fill in the blanks with the correct form of 〜んです.

1. おなかが（　　　　）。
   (My stomach hurts, that’s why…)
   
2. 宿題しゅくだいを（　　　　）。
   (I didn’t do the homework, you see…)
   
3. あの人ひとは先生せんせい（　　　　）。
   (That person is a teacher.)
   
4. 朝あさから何なにも（　　　　）。
   (I haven’t eaten anything since this morning…)
   
5. 今日きょうは車くるまが（　　　　）。
   (My car isn’t working today…)
   
   

Here are the answers for each question.

1. おなかが 痛いたいんです。
2. 宿題しゅくだいを しなかったんです。
3. あの人ひとは 先生せんせいなんです。
4. 朝あさから何なにも 食たべていないんです。
5. 今日きょうは車くるまが こわれているんです。

By using 〜んです, you’ll sound more natural, thoughtful, and expressive in your Japanese conversations. Try it next time when explaining how you feel or asking someone what’s going on!

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