📘 Grammar 34: How to Use ~기 때문에 – Expressing Reason in Korean

📘 How to Use ~기 때문에 – Expressing Reason in Korean

Do you want to say “Because I was busy,” “I couldn't go because it rained,” or “I’m tired because I studied late” in Korean?

Then it’s time to learn ~기 때문에, a formal and clear grammar pattern used to express **reasons and causes** in Korean.

This structure is commonly used in writing, polite speech, and explanations. In this lesson, we’ll look at how it’s formed, when to use it, and how it compares to other “because” forms like ~아서/어서.

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📌 What Does ~기 때문에 Mean?

~기 때문에 means “because (of)” or “due to the fact that…”

✔️ It’s used when you want to clearly state a reason or cause.

Structure:

• Verb stem + 기 때문에
• Adjective stem + 기 때문에

Used with two clauses: [Reason clause] + 기 때문에 + [Result clause]

📘 Example Sentences

• 바빴기 때문에 못 갔어요 – Because I was busy, I couldn’t go
  bappat-gi ttae-mun-e mot gat-seo-yo
• 비가 왔기 때문에 지각했어요 – I was late because it rained
  bi-ga wat-gi ttae-mun-e ji-gak-haet-seo-yo
• 늦게 공부했기 때문에 피곤해요 – I’m tired because I studied late
  neut-ge gong-bu-haet-gi ttae-mun-e pi-gon-hae-yo
• 시험이 있기 때문에 못 만나요 – I can't meet you because I have an exam
  si-heom-i it-gi ttae-mun-e mot man-na-yo

📊 Grammar Table – Verb + 기 때문에

Verb/Adjective	~기 때문에 Form	Meaning	Romanization
바쁘다 (to be busy)	바쁘기 때문에	Because I’m busy	bappeu-gi ttae-mun-e
가다 (to go)	가기 때문에	Because (someone) goes	ga-gi ttae-mun-e
춥다 (to be cold)	춥기 때문에	Because it’s cold	chup-gi ttae-mun-e
공부하다 (to study)	공부했기 때문에	Because (someone) studied	gong-bu-haet-gi ttae-mun-e

💡 Comparison: ~기 때문에 vs ~아서/어서

Expression	Use	Formality	Example
~기 때문에	Clear cause-and-effect, more formal	High	늦었기 때문에 못 갔어요
~아서/어서	Casual reason, natural in speech	Low/Neutral	늦어서 못 갔어요

✔️ Use ~기 때문에 in writing, explanations, or formal situations

❗ Common Mistakes

• ❌ 바빠서 시험을 못 봤어요 (correct but casual) → ✅ 바빴기 때문에 시험을 못 봤어요
• Don't confuse “때문에” alone with “~기 때문에” (noun vs verb form)
• “~기” turns the verb into a noun to be followed by “때문에”

🧪 Mini Quiz – Test Yourself!

1. Translate: “Because I didn’t sleep, I’m tired.”
   a) 안 자서 피곤해요
   b) 자지 않았기 때문에 피곤해요
   
   Click to Show Answer

   ✅ b) 자지 않았기 때문에 피곤해요

2. Which one is more formal?
   a) 늦어서 못 갔어요
   b) 늦었기 때문에 못 갔어요
   
   Click to Show Answer

   ✅ b) 늦었기 때문에 못 갔어요

3. What’s the correct form for “Because I study”?
   a) 공부기 때문에
   b) 공부하기 때문에
   
   Click to Show Answer

   ✅ b) 공부하기 때문에

✅ Conclusion

Now you know how to express reasons politely and clearly in Korean using ~기 때문에.

• Use with verb and adjective stems
• Attach ~기 to the stem + 때문에
• Follow with a result clause (못 했어요, 늦었어요, etc.)

Try these:

• “Because I didn’t eat” → 먹지 않았기 때문에
• “Because she was sick” → 아팠기 때문에

📘 Coming Up Next

Next lesson: How to Use ~아/어야 돼요 – Expressing Obligation in Korean
Learn how to say “You have to study,” “I must go,” and more!

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Related Keywords:
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