고 나서 (after completion) - After Doing

This pattern connects two actions in a timeline. The first action must reach its end point. It’s not just about one thing following another. It’s about the completion of the first task. You are saying, "Once I finished doing X, I did Y." It’s very common in daily conversation. You’ll hear it when people talk about routines. You’ll see it in recipes or instructions. It sounds more deliberate than the simple -고. It tells the listener that action A is a prerequisite. You wouldn't skip to B without finishing A first.

1. 1Take your first verb (the one you finish).
2. 2Remove the 다 to find the verb stem.
3. 3Simply add 고 나서 to that stem.
4. 4Follow it with your next sentence or action.
5. 5먹다 (to eat) becomes 먹고 나서.
6. 6하다 (to do) becomes 하고 나서.
7. 7읽다 (to read) becomes 읽고 나서.
8. 8There are no tricky batchim (final consonant) rules here. Whether the stem ends in a vowel or a consonant, it’s the same. It’s one of the friendliest patterns to conjugate! Even irregular verbs behave well with this one.

Use 고 나서 when the order of actions matters. Use it for chores, like washing dishes before watching TV. Use it for work, like finishing a report before a meeting. It’s great for emphasizing a break or a transition. For example, "After finishing my workout, I took a shower." It shows you weren't just exercising and showering at once. You finished the sweat session first! It's perfect for when you want to sound organized. Native speakers use it to avoid ambiguity. If you just use -고, it might sound like a loose list. 고 나서 makes it a structured timeline.

Don't use 고 나서 for things that happen naturally together. For example, putting on socks and then shoes. Those are almost one continuous action. Don't use it for movement verbs like 가다 (to go) or 오다 (to come) in simple sequences. For those, 가서 or 오고 usually feels more natural. Also, avoid it for very short, trivial actions. You wouldn't say "After finishing blinking, I looked at the cat." That's just weird. It’s meant for intentional actions with a clear beginning and end. If there's no sense of "finishing," don't use it. Just stick to the simple -고 for basic lists.

One big mistake is trying to put tense in the first verb. Don't say 먹었고 나서 (✗). The tense always goes at the very end of the whole sentence. The 고 나서 part stays neutral. Another slip-up is using it with adjectives. 고 나서 is strictly for verbs because adjectives don't "finish." You can't "finish being tall" and then do something else. Some learners also use it when the two actions overlap. If you’re listening to music *while* cleaning, this isn't the rule for you. This is for the "Action A -> DONE -> Action B" sequence. Keep the boundary sharp!

How does this differ from -(으)ㄴ 후에? Both mean "after." However, -(으)ㄴ 후에 is more formal and general. You can use it for long periods, like "After graduating college." 고 나서 feels more immediate and active. It's about the physical act of finishing. Then there's the simple -고. That's just a sequence, like "I ate and studied." It doesn't emphasize that the eating was 100% done. 고 나서 is the emphatic version. It’s like saying "After I was finally done eating, I studied." Use -고 for casual lists and 고 나서 for clear steps.