길래 (observational reason) - So, Because (I Saw/Heard)

This pattern connects two clauses. The first clause is the "trigger" or the thing you observed. The second clause is your "reaction" or what you did because of that observation. It is like a cause-and-effect chain, but the cause must be something you perceived with your senses. You are not just giving a logical reason. You are sharing a personal story. "I saw the weather was nice, so I went for a walk." The weather being nice is the observation. Going for a walk is the reaction. It is a very active way of speaking. You are telling your listener why you reacted the way you did.

1. 1Using 길래 is quite simple once you get the hang of it.
2. 2For Verbs and Adjectives: Just take the verb stem and add -길래.
3. 3가다 (to go) becomes 가길래
4. 4먹다 (to eat) becomes 먹길래
5. 5예쁘다 (to be pretty) becomes 예쁘길래
6. 6For Past Tense: Add -었/았/였길래. This is used when the observation itself happened in the past.
7. 7왔다 (came) becomes 왔길래
8. 8했다 (did) becomes 했길래
9. 9For Nouns: Use -(이)길래.
10. 10학생 (student) becomes 학생이길래
11. 11친구 (friend) becomes 친구길래
12. 12Pro-tip: Don't overthink the tenses too much. If you are describing a chain of events that already happened, you can often stick to the basic stem + 길래 in the first part and put the past tense at the end of the sentence.

Use 길래 when you want to explain your choices based on external factors.

• Seeing something: You see a "Sale" sign, so you go inside. 세일하길래 들어갔어요.
• Hearing something: You hear your friend is sick, so you call them. 아프다길래 전화했어요.
• Feeling something: The room feels hot, so you open the window. 덥길래 창문을 열었어요.
• Ordering Food: You saw someone eating a delicious-looking stew, so you ordered the same. 맛있어 보이길래 저도 그걸로 시켰어요.
• Job Interviews: You might explain why you applied for a position. "I heard this company has a great culture, so I applied."
• Asking Directions: "I saw you looking at a map, so I came to help."

It feels very reactive. It is perfect for those "on the fly" decisions we make every day.

There are a few "No-Go" zones for 길래.

• Formal Writing: Avoid this in formal essays or professional reports. In those cases, use -기에. 길래 is definitely a "chatting with friends" or "talking to colleagues" kind of vibe.
• Commands and Suggestions: You cannot usually follow 길래 with an imperative like "Do this!" or a suggestion like "Let's do this." For example, you wouldn't say "Since it's raining, let's buy an umbrella" using 길래. Use -니까 for that instead.
• Third Person Subjects (Mostly): Usually, the second part of the sentence (the reaction) should be about *you* (the speaker). If you say "Since it rained, Minji bought an umbrella," 길래 feels a bit awkward. It is meant to explain *your* logic.

1. 1The Subject Swap: Beginners often try to explain someone else's actions. ✗ 친구가 배고프길래 밥을 먹었어요. (Since my friend was hungry, he/she ate rice). This sounds like you ate the rice because your friend was hungry! Keep the second clause focused on your own action.
2. 2Mixing with -니까: Don't use 길래 for general logical facts. If you say "Because 1+1 is 2, I wrote 2," use -니까. 길래 needs that "I observed this" flavor.
3. 3Formal Overload: Don't use it in a speech to a large audience. It might sound a bit too casual or even slightly blunt.
4. 4The "Why" Question Trap: Sometimes learners use it to answer a "Why?" question where a simple -어서 would be better. Only use it if you want to emphasize the observation part.

• 길래 vs. -아서/어서: -아서/어서 is the general "so/because." It is neutral. 길래 is specific to your observation. Use 길래 when you want to show that you were reacting to something you saw or heard.
• 길래 vs. -니까: -니까 is often used when the reason is something both people know, or when giving commands. 길래 is purely your personal reason based on what you just noticed.
• 길래 vs. -기에: These are basically the same meaning, but -기에 is the formal, written version. Think of 길래 as the cool younger sibling and -기에 as the serious professor.