Key facts
- 19 time and sequence patterns each have a lesson, with levels A1 3, A2 5, B1 7, B2 3 and C1 1 (editorial estimates mapped loosely to TOPIK I and II).
- Each pattern has its own lesson page with a formation table, audio examples and practice with answers.
- Three A1 patterns cover most daily needs: -(으)ㄹ 때 ("when"), -기 전에 ("before") and -(으)ㄴ 후에 ("after").
- Comparison pages exist for -(으)ㄹ 때 vs -(으)면, -다가 vs -(으)면서 and -고 나서 vs -(으)ㄴ 후에.
Listen to the sentence that shows the simplest pattern.
The next section defines the topic.
What Are the Korean When Grammar Patterns?
They are the connective endings that place two actions in time. A connective ending is a word ending that joins one clause to the next. A time pattern tells the listener whether the first action comes before, after or during the second one, or whether it lasts up to a point. English uses "when", "before", "after", "while", "until" and "as soon as" for the same job.
Korean has many because each pattern carries a different detail. Some say the first action is finished. Some say the actions overlap. Some say the second action follows at once. Some also carry a feeling, such as discovery. The wider area is described in Korean grammar, and the other connector groups are listed on the Korean connectors page.
Which Pattern Should You Learn First?
Start with -(으)ㄹ 때 ("when"), which is at level A1. Then learn -기 전에 and -(으)ㄴ 후에, the "before" and "after" pair. Next come the A2 patterns -(으)면서, -고 나서, -는 동안, -(으)ㄹ 때까지 and -(으)ㄴ 지. The B1 patterns add speed, interruption, discovery and side tasks.
A learner who has not yet met the polite ending -아요/어요 and the past tense should review Beginner Grammar first.
Quick Chooser
| Meaning wanted | Pattern | Level |
|---|---|---|
| "when, at the time of" | -(으)ㄹ 때 | A1 |
| "before" | -기 전에 | A1 |
| "after" | -(으)ㄴ 후에 | A1 |
| "while" | -(으)면서 | A2 |
| "as soon as" | -자마자 | B1 |
| "in the middle of doing X, then Y" | -다가 | B1 |
The Patterns, Grouped by Meaning
Each entry below has a short description, one example sentence with Revised Romanization (RR, the official Latin spelling, shown only as an aid) and audio.
Before, after and at the Time Of
-(으)ㄹ 때
This lesson teaches the basic "when" pattern for verbs, adjectives and nouns (noun + 때). The tense of the main verb tells you when it happened, and the -(으)ㄹ 때 form stays the same whatever that tense is. Example: 한국에 갈 때 비행기를 탈 거예요. (hanguge gal ttae bihaenggireul tal geoyeyo.) "When I go to Korea, I will take a plane." Level A1.
Read the full lesson: -(으)ㄹ 때 grammar.
-기 전에
This lesson teaches "before". The verb before 전에 never takes a past or future ending, even when the main verb is in the past. Example: 자기 전에 이를 닦아요. (jagi jeone ireul dakkayo.) "I brush my teeth before sleeping." Level A1.
Read the full lesson: -기 전에 grammar.
-(으)ㄴ 후에
This lesson teaches "after". The first clause keeps a fixed -(으)ㄴ form, and 후에 sounds a little more formal than 뒤에. Example: 수업이 끝난 후에 점심을 먹어요. (sueobi kkeunnan hue jeomsimeul meogeoyo.) "After class ends, I eat lunch." Level A1.
Read the full lesson: -(으)ㄴ 후에 grammar.
-고 나서
This lesson teaches "after finishing X, then Y". It stresses that the first action is complete before the second begins. Example: 숙제를 하고 나서 놀아요. (sukjereul hago naseo norayo.) "I play after finishing my homework." Level A2.
Read the full lesson: -고 나서 grammar.
During and at the Same Time
-(으)면서
This lesson teaches "while" for two actions that overlap, done by the same person. With adjectives and nouns it can also mean "and also". Example: 음악을 들으면서 운전해요. (eumageul deureumyeonseo unjeonhaeyo.) "I drive while listening to music." Level A2.
Read the full lesson: -(으)면서 grammar.
-는 동안(에)
This lesson teaches "while, during" for a period of time. The subjects of the two clauses may be different. Example: 제가 요리하는 동안 아이는 숙제를 했어요. (jega yorihaneun dongan aineun sukjereul haesseoyo.) "While I was cooking, the child did homework." Level A2.
Read the full lesson: -는 동안(에) grammar.
-다가
This lesson teaches "in the middle of doing X, then Y". The first action is interrupted or switched to another, and both actions have the same subject. Example: 공부하다가 잠이 들었어요. (gongbuhadaga jami deureosseoyo.) "I fell asleep while studying." Level B1.
Read the full lesson: -다가 grammar.
-(으)ㄴ 채로
This lesson teaches "while still, with X still on". The first state continues while the second action happens, often with a note of surprise. Example: 옷을 입은 채로 잤어요. (oseul ibeun chaero jasseoyo.) "I slept with my clothes on." Level B1.
Read the full lesson: -(으)ㄴ 채로 grammar.
- Also read: -는 사이(에) (while, in the meantime), level B2.
Right Away
-자마자
This lesson teaches "as soon as". The second action follows the first at once, and the subjects may be the same or different. Example: 집에 도착하자마자 샤워했어요. (jibe dochakajamaja syawohaesseoyo.) "I showered as soon as I got home." Level B1.
Read the full lesson: -자마자 grammar.
- Also read: -기가 무섭게 (the moment, no sooner than), level C1.
- Also read: -(으)ㄴ/는 대로 (as soon as; exactly as), level B2.
Until and Since
-(으)ㄹ 때까지
This lesson teaches "until". The action in the main clause continues up to the point named in the first clause. Example: 비가 그칠 때까지 기다릴게요. (biga geuchil ttaekkaji gidarilgeyo.) "I will wait until the rain stops." Level A2.
Read the full lesson: -(으)ㄹ 때까지 grammar.
-(으)ㄴ 지
This lesson teaches "since". It reports how long ago an event started or finished, and it always includes a length of time. Example: 그를 만난 지 오래됐어요. (geureul mannan ji oraedwaesseoyo.) "It has been a long time since I met him." Level A2.
Read the full lesson: -(으)ㄴ 지 grammar.
Finding Something Out
-다 보니(까)
This lesson teaches "as I kept doing X, I realised Y". It describes a result that appears gradually while an action goes on. Example: 한국어를 공부하다 보니 재미있어졌어요. (hangugeoreul gongbuhada boni jaemiisseojyeosseoyo.) "As I kept studying Korean, it became fun." Level B1.
Read the full lesson: -다 보니(까) grammar.
-아/어 보니(까)
This lesson teaches "when I tried it, I found out". It describes a discovery after trying something, and the second clause states the finding. Example: 먹어 보니까 맛있었어요. (meogeo bonikka masisseosseoyo.) "When I tried it, it tasted good." Level B1.
Read the full lesson: -아/어 보니(까) grammar.
- Also read: -았/었더니 (I did X and then noticed Y), level B2.
While You Are Already Doing Something
-는 김에
This lesson teaches "while at it, since I'm already". The first action is already planned, and the second is added at the same time or place. Example: 서울에 가는 김에 친구도 만날 거예요. (seoure ganeun gime chingudo mannal geoyeyo.) "While I'm going to Seoul, I will meet a friend too." Level B1.
Read the full lesson: -는 김에 grammar.
-는 길에
This lesson teaches "on the way to", usually with 가다 and 오다. The second action happens on the road, before you arrive. Example: 집에 가는 길에 빵을 샀어요. (jibe ganeun gire ppangeul sasseoyo.) "I bought bread on the way home." Level B1.
Read the full lesson: -는 길에 grammar.
How Do You Choose between Look-Alike Patterns?
Several pairs look alike. Here are the tests that settle most choices.
- -(으)ㄹ 때 or -(으)면? Both can be translated as "when". -(으)ㄹ 때 names a time. -(으)면 names a condition ("if"). The lesson on -(으)ㄹ 때 vs -(으)면 gives a decision rule.
- -(으)면서 or -다가? -(으)면서 means two actions overlap, and both continue. -다가 means the first action stops or switches to another. See -다가 vs -(으)면서.
- -고 나서 or -(으)ㄴ 후에? Both mean "after". -고 나서 stresses that the first action is finished, and -(으)ㄴ 후에 sounds a little more formal. See -고 나서 vs -(으)ㄴ 후에.
- -자마자, -(으)ㄴ/는 대로 or -기가 무섭게? All three mean the second action follows at once. -자마자 is the plain choice, -기가 무섭게 adds strong speed, and -(으)ㄴ/는 대로 needs a future main clause. Compare them in -자마자 vs -(으)ㄴ/는 대로.
- -아/어 보니(까) or -다 보니(까)? -아/어 보니(까) reports what you found out after trying something once. -다 보니(까) reports a result that appeared while you kept doing something. See -아/어 보니(까) and -다 보니(까).
- -는 동안 or -는 사이에? -는 동안 covers the whole period. -는 사이에 points to a gap in which something happened without notice; see -는 사이(에).
Where Can You Practise?
Each lesson ends with four tasks, an answer key and a quiz. Start with the three A1 lessons, then follow the order in the quick chooser. Listen to each example clip, say the sentence aloud, and then write one sentence of your own. Pay attention to tense: many of these patterns do not allow a tense marker before the ending, so the main verb carries it. For example, 자기 전에 is always in the bare form, even when the main verb is in the past.
What Does This Section Not Cover?
This section covers time and sequence connectors only. Other connectors are in sibling groups on the Korean connectors page. Particles, tenses, negation, speech levels, modifiers, nominalizers and auxiliary verbs have their own sections of the Korean grammar hub. The comparison lessons cover the pairs above and no other pairs. To plan by level, use Beginner Grammar.
About this page. Last updated 2026-10-09. Revised Romanization follows the national rules and is shown only as a learning aid.
Frequently Asked Questions
What Does Korean When Grammar Include?
They are the connective endings that place one action in time next to another: -(으)ㄹ 때 (when), -기 전에 (before), -(으)ㄴ 후에 (after), -(으)면서 (while), -자마자 (as soon as) and more. There are 19, and each has a full lesson; the A1 to B1 ones have a short example here.
Which Pattern Should I Learn First?
Start with -(으)ㄹ 때 ("when"), at level A1, then learn -기 전에 ("before") and -(으)ㄴ 후에 ("after"). These three cover most daily needs. Next come the A2 patterns, such as -(으)면서 ("while") and -고 나서 ("after finishing"). Follow the quick chooser table and the level labels for the next steps.
How Do I Know Which Pattern Fits My Sentence?
Ask what the two actions do in time. Does one come before or after the other? Do they overlap? Does the second follow at once? Does the first stop in the middle? The quick chooser and the look-alike section on this page match each answer to a pattern, and the comparison lessons give a decision rule for close pairs.
Are These Patterns on the TOPIK Exam?
They are common in textbooks, conversations and reading texts, so they help at TOPIK I and II. The level labels on this page are editorial estimates, not an official list. Learners who plan to take the test should know the A1 and A2 patterns well and recognise the B1 and later ones in reading.
Where Are the Comparison Pages?
Three comparison pages cover the pairs learners confuse most: -(으)ㄹ 때 vs -(으)면, -다가 vs -(으)면서 and -고 나서 vs -(으)ㄴ 후에. Each gives a decision rule, side-by-side examples and practice. They are linked in the section on look-alike patterns above, and a fourth covers -자마자 vs -(으)ㄴ/는 대로.