고 나서 (after doing, and then)

At its core, 고 나서 is a connective ending. It links two verbs together. You have Verb 1 (the one that finishes) and Verb 2 (the one that starts). You simply take the stem of Verb 1 and attach 고 나서. The '고' part handles the 'and then' aspect, while '나서' comes from the verb 나다 (to emerge/finish), giving it that extra 'after finishing' weight. It functions like a bridge. You cross the bridge only after you've finished everything on the first side. One of the best things about this pattern is its simplicity. It doesn't care about the tense of the first verb. You never have to worry about past or future markers in the middle of the sentence. The entire sentence's tense is decided right at the very end. This keeps your speech clean and prevents you from getting tongue-tied with complex conjugations. It is a reliable, sturdy structure that works in both casual and formal settings. Whether you are talking to your boss or your best friend, 고 나서 keeps your timeline straight without any fuss.

1. 1Getting this right is easier than ordering your favorite bubble tea. There are no tricky exceptions or irregular changes to worry about here! Follow these simple steps:
2. 2Identify your first verb (the one that must finish first).
3. 3Drop the dictionary ending 다 to get the verb stem.
4. 4Add 고 나서 directly to that stem.
5. 5It doesn't matter if the stem ends in a vowel or a consonant. It's the same for everyone!
6. 6For 가다 (to go): The stem is 가. Add 고 나서 to get 가고 나서.
7. 7For 먹다 (to eat): The stem is 먹. Add 고 나서 to get 먹고 나서.
8. 8For 읽다 (to read): The stem is 읽. Add 고 나서 to get 읽고 나서.
9. 9For 공부하다 (to study): The stem is 공부하. Add 고 나서 to get 공부하고 나서.
10. 10Yes, even irregular verbs like 듣다 (to listen) or 돕다 (to help) stay simple here. 듣다 becomes 듣고 나서. No weird 'ㄷ' to 'ㄹ' changes in this specific spot! It is one of the few places in Korean grammar where you can truly relax and just stick the pieces together.

You should reach for 고 나서 whenever the completion of the first task is the most important part of your sentence. Use it when you are giving instructions. For example, 'After checking the map, turn left.' If they turn left *before* checking the map, they'll get lost! Use it for daily routines where the sequence is logical, like 'I drink coffee after I wake up.' Use it in professional settings to show you are thorough, like 'I will send the email after I finish the report.' It’s also great for social scenarios. If you're at a restaurant in Korea, you usually eat first and *then* pay. So you'd say, '밥을 먹고 나서 계산해요.' It emphasizes that the meal is over before the wallet comes out. It’s also very useful for 'checking' or 'considering' actions. 'I'll decide after I think about it' (생각해 보고 나서 결정할게요) sounds much more mature and careful than a simple 'and then.' It shows you are taking the time to finish the thinking process completely.

While 고 나서 is powerful, it’s not for every situation. First, never use it with adjectives. You can't be 'after being pretty' or 'after being tall' using this pattern. It is strictly for actions (verbs). Second, don't use it for things that happen naturally or simultaneously. If you are 'walking while talking,' use -면서 instead. If the actions are just part of a natural flow where the first one leads into the second (like 'waking up and getting out of bed'), a simple -아서/어서 is usually better. 고 나서 feels a bit too heavy for tiny, seamless actions. It’s like using a sledgehammer to crack a nut. Also, avoid using it for 'coming' or 'going' when the focus is on the state of being there. If you 'went to the park and met a friend,' the focus is often on being at the park, so 가서 is the standard choice. 가고 나서 would imply that the act of *traveling* to the park was a project you finished before the meeting started. It sounds a bit robotic in that context.

The biggest trap you'll face is trying to put a tense on the first verb. It’s so tempting to say 먹었 고 나서 (after having eaten), but don't do it! The '고' already implies the sequence, and '나서' implies the completion. Adding a past tense marker like 었 makes the sentence grammatically 'noisy' and incorrect. Keep the first verb in its base stem form. Another common slip-up is confusing it with -아서/어서. Remember, -아서/어서 often shows a cause-and-effect relationship or a very tight connection. 고 나서 is just about the timeline. If you say 비가 오고 나서 땅이 젖었어요 (The ground got wet after it rained), it's okay, but it sounds like the rain finished, packed its bags, and then the ground decided to get wet. Usually, the ground gets wet *because* it's raining, so -아서 fits better there. Finally, don't forget the '고'. Some people try to say 먹나서, which just sounds like you've forgotten a piece of the puzzle. It’s a three-part package: Stem + 고 + 나서.

How does this stack up against -고 or -(으)ㄴ 후에?

• -고: This is the 'simple and.' 'I ate and I slept.' It doesn't emphasize that you finished eating before you slept. You might have still been chewing! It’s just a list of events.
• -(으)ㄴ 후에: This is the formal 'after.' It’s very common in writing and speeches. While it means the same thing as 고 나서, it lacks that conversational 'punch.' 고 나서 feels more active and immediate. If - (으)ㄴ 후에 is a polite sign in a hallway, 고 나서 is a friend telling you what to do next.
• -아서/어서: As mentioned, this is for actions that are glued together. If you go to a cafe and drink coffee, you use 가서. If you go to a cafe, finish your shift working there, and then go somewhere else entirely, you might use 가고 나서 to show that the first 'going' event is totally over. Use 고 나서 when you want to put a clear 'period' at the end of Action A before Action B starts.