길래 (so, because I saw/heard)

At its core, -길래 explains why you did something based on a situation you observed. You aren't the cause of the first part; the world around you is. You are simply reacting to it. Imagine you’re at a job interview. You notice the interviewer looks thirsty, so you offer them a bottle of water. That observation—the thirsty look—is the trigger. -길래 is mostly used in spoken Korean. It feels much warmer and more spontaneous than the stiff -어서 or the slightly more logical -니까. It’s like telling a story to a friend. You’re giving them the "why" behind your choices by pointing at the environment. Yes, even native speakers mess this up sometimes by trying to use it for their own internal feelings, but you'll be ahead of the curve! Think of it like a grammar traffic light: the observation is the green light that makes you go and do something.

1. 1Joining -길래 to your sentences is actually quite simple. You don't need to worry about complex consonant endings here!
2. 2For Verbs and Adjectives (Present Tense): Just take the verb stem and add -길래.
3. 3가다 (to go) → 가길래
4. 4예쁘다 (to be pretty) → 예쁘길래
5. 5맛있다 (to be delicious) → 맛있길래
6. 6For Past Tense: Add the past tense marker 었/았/였 to the stem first, then add -길래.
7. 7먹다 (to eat) → 먹었길래
8. 8하다 (to do) → 했길래
9. 9For Nouns: Use 이길래 after a consonant or 길래 after a vowel (though 이길래 is often used for both in casual speech).
10. 10친구 (friend) → 친구길래
11. 11학생 (student) → 학생이길래

Use -길래 when you want to justify your action based on something you noticed in someone else or the environment.

• Social Scenarios: You saw a friend looking tired, so you bought them coffee.
• Shopping: The shoes were 50% off, so you bought two pairs (we've all been there).
• Food: The ramen looked so spicy on the menu, so you ordered the mild version instead.
• Weather: It looked like it was going to rain, so you grabbed an umbrella.

It’s perfect for those moments where you are explaining your behavior to someone else. It provides context. Without it, your action might seem random. With it, you sound observant and thoughtful.

There are a few "no-go" zones for -길래. First, don't use it in formal writing like essays or news reports; it’s too casual for that. Use -기에 instead if you need to be fancy. Second, the subject of the first part (the reason) should usually not be you. You can't say "Because I was hungry, I ate," using -길래. That's for -어서. Instead, it’s "Because the food looked good, I ate." Third, don't use -길래 in the first clause if you are giving a command or making a suggestion in the second clause. No 하세요 or 할까요 endings here! It’s strictly for stating what you already did or are currently doing.

The biggest trap is the "Subject Switch." Remember: The first part is the observation (external), and the second part is your reaction (1st person).

• ✗ 내가 배고프길래 밥을 먹었어요. (Wrong: Subject of reason is "I").
• ✓ 동생이 배고프다길래 밥을 줬어요. (Correct: I observed my brother was hungry).

Another mistake is using it for future plans. -길래 is about reacting to something that is already happening or has happened. If you use it to talk about a hypothetical future, it sounds very strange. It’s like trying to use a map of London to find your way around Seoul—just doesn't work!

• -길래 vs. -어서: -어서 is a general "because." It works for internal reasons ("I'm tired") and external ones. -길래 is specialized for "I saw/heard/noticed."
• -길래 vs. -니까: -니까 often implies a logical discovery or a reason the listener already knows. -길래 is more about your personal sensory observation as a trigger for action.
• -길래 vs. -기에: These are basically twins, but -기에 is the one who wears a tuxedo to every party. Use -길래 with friends and -기에 in speeches or literature.