(으)ㄴ/는 후에 (after doing)

This pattern attaches directly to verb stems. It acts like an adjective for the past. You are basically saying 'the state of having done X'. The word 후 means 'after' or 'later'. The particle 에 marks the time. Together, they create a clear 'after' marker. It is like a checkmark on your to-do list. Once the first box is checked, the next action flows. It works with all tenses in the second clause. You can say 'I did X after Y'. You can say 'I will do X after Y'. The (으)ㄴ part always stays the same. It is a stable anchor in your sentences. Think of it like a grammar traffic light. The first action gets the green light to finish. Then the second action can enter the intersection.

1. 1Building this rule is like playing with Lego blocks. You just need to check the bottom of the verb stem.
2. 2If the stem ends in a vowel, add ㄴ 후에.
3. 3가다 (to go) becomes 간 후에.
4. 4보다 (to see) becomes 본 후에.
5. 5If the stem ends in a consonant, add 은 후에.
6. 6먹다 (to eat) becomes 먹은 후에.
7. 7읽다 (to read) becomes 읽은 후에.
8. 8Watch out for the sneaky ㄹ irregulars! The ㄹ drops away.
9. 9만들다 (to make) becomes 만든 후에.
10. 10For ㅂ irregulars, the ㅂ turns into 우.
11. 11돕다 (to help) becomes 도운 후에.
12. 12For ㄷ irregulars, the ㄷ turns into ㄹ.
13. 13듣다 (to listen) becomes 들은 후에.

Use this whenever you need a clear sequence. It is perfect for daily routines. 'After I shower, I sleep.' It is essential for giving directions. 'After you cross the street, turn left.' It is also great for professional settings. Imagine a job interview. You might say, 'After I graduate, I want to work here.' In a restaurant, you could say, 'I will order after my friend arrives.' It shows you are thinking ahead. It connects your thoughts logically. It is also very helpful when explaining a process. 'First, boil the water. After the water boils, add the noodles.' It prevents confusion. Nobody wants to add noodles to cold water, right?

This rule has some boundaries. First, avoid using it with adjectives. You cannot really say 'after being pretty'. It sounds very strange in Korean. Stick to action verbs. Second, don't use it for things that happen at the same time. If you are eating while watching TV, use -(으)면서 instead. (으)ㄴ 후에 requires a gap. Action A must be totally done. Also, don't use it with nouns directly. For nouns, you just use 명사 + 후에. For example, 수업 후에 instead of 수업한 후에. Though both work, the noun version is shorter. Finally, don't double up on the past tense. Never say 갔은 후에. The (으)ㄴ already does the heavy lifting for you.

The most common slip-up is forgetting the ㄴ or 은. Many learners just say 가 후에. That sounds like 'go after' in English, but it's broken Korean. It must be 간 후에. Another mistake is using the present tense 는. Saying 먹는 후에 is a big no-no. It makes it sound like you are still eating while the next thing happens. It is like trying to put your shoes on while you are still running. Just breathe and remember the ㄴ. Also, be careful with the space. It is 간 (space) 후에. Writing it as one word is a minor spelling error. Even native speakers do it sometimes, but you can do better!

You might see -고 나서 or -(으)ㄴ 다음에. These are like siblings. They all mean 'after'. (으)ㄴ 다음에 is almost 100% interchangeable. You can swap them whenever you want. It's like choosing between 'after' and 'following'. -고 나서 is a bit stronger. it emphasizes that the first action is *completely* finished and gone. If you want to be extra clear, use -고 나서. If you want a general, all-purpose 'after', stick with (으)ㄴ 후에. There is also -고, which just means 'and then'. -고 is much simpler and faster. Use (으)ㄴ 후에 when the timing really matters.