Because of V-ing (-기 때문에)
-기 때문에
Expresses a reason or cause, meaning 'because of doing something'.
Pattern
Verb/Adjective stem + -기 때문에 / Noun + 때문에
Explanation
-기 때문에 is a formal way to express reason or cause. It combines the nominalizer -기 with 때문에 (because of). This pattern is more formal than -(으)니까 or -아/어서 and is commonly used in writing, presentations, and formal speech.
The verb stem attaches to -기, and 때문에 follows. For example, 비가 오기 때문에 means 'because it rains'. For nouns, you use 때문에 directly: 비 때문에 (because of rain).
This grammar point is especially important for TOPIK essays and formal explanations. While -(으)니까 is common in casual speech, -기 때문에 is preferred when you want to sound more objective or academic. It emphasizes the logical relationship between cause and effect.
Examples
비가 오기 때문에 우산을 가져가세요.
Biga ogi ttaemune usaneul gajyeogaseyo.
Because it's raining, please take an umbrella.
바쁘기 때문에 못 갔어요.
Bappeugi ttaemune mot gasseoyo.
Because I was busy, I couldn't go.
건강하기 때문에 걱정하지 마세요.
Geonganghagi ttaemune geokjeonghaji maseyo.
Because I'm healthy, please don't worry.
시험 때문에 많이 공부했어요.
Siheom ttaemune mani gongbuhasseoyo.
I studied a lot because of the exam.
Common Mistakes
Wrong
비가 오기때문에 못 가요.
Correct
비가 오기 때문에 못 가요.
There should be a space between -기 and 때문에. They are separate units.
Wrong
바쁜기 때문에 못 갔어요.
Correct
바쁘기 때문에 못 갔어요.
Attach -기 directly to the verb/adjective stem (바쁘다 → 바쁘기), not to the modifier form.
Related Grammar Points
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