Korean Connectors: Clause-Linking Endings Explained

Listen to the sentence that shows the simplest connector.

The next section defines what a connector is.

What Are Korean Connectors?

Korean connectors are connective endings (연결 어미, yeongyeol eomi): endings that attach to the stem of a verb or adjective and link its clause to the next one. A clause is a group of words built around one verb or adjective. A stem is a dictionary form without its final 다, such as 먹 in 먹다. English uses separate words such as "and", "but", "because" and "if". Korean attaches the same meanings to the end of the first clause.

Take 비가 와서 집에 있어요 ("Because it rains, I stay home"). The ending -아서 (here 와서) sits on the verb 오다, and it links the rain to staying home. The final verb 있어요 carries the tense and the politeness. This pattern is the same for every connector: the connector goes in the middle of the sentence, and the last verb finishes it.

Two things set connectors apart from other endings. First, many have two or three forms, shown in brackets such as -(으)면 (면 after a vowel, 으면 after a consonant). Second, irregular stems change only before endings that start with a vowel, so vowel-initial connectors such as -아/어서 and -(으)면 trigger them, while consonant-initial ones such as -고 and -지만 do not. The next section gives a route through the patterns.

Which Pattern Should You Learn First?

Start with -고, then add the time and purpose basics, then the A2 core. The 74 patterns are not equally common, and the levels below are an editorial estimate based on common textbook order and TOPIK I and II level descriptions, not an official syllabus.

A study order that works for most learners has three stages:

1. Stage 1: A1 basics. Read -고, -(으)ㄹ 때, -기 전에, -(으)ㄴ 후에 and -(으)러.
2. Stage 2: the A2 core. Read -아/어서, -(으)면, -지만, -(으)ㄴ/는데, -(으)니까 and -아/어도.
3. Stage 3: B1 and above. Pick groups by need: the written forms for reading, and the contrast and cause groups for argument.

Who can skip ahead? A learner who already uses -고, -아/어서 and -(으)면 in speech can start at stage 2. The full list by level is on the Beginner Grammar page. The next section describes each group.

The Patterns, Grouped by Meaning

The 74 patterns fall into six groups, and each group has its own page. Every entry below has a short description, one example sentence with Revised Romanization (RR, the official Latin spelling, shown only as an aid) and audio.

And / but Connectors

This group has 9 patterns from A1 to B2. It covers listing actions, choosing between options and contrasting clauses, with -고, -거나, -지만 and -(으)ㄴ/는데 at the core. Example: 저는 아침을 먹고 학교에 가요. (jeoneun achimeul meokgo hakgyoe gayo.) "I eat breakfast and go to school." Spoken [저는 아치믈 먹꼬 학꾜에 가요]. See And / But Connectors for the full set.

Cause and Reason

This group has 16 patterns from A2 to B2. It covers "because", "so" and "thanks to", with -아/어서, -(으)니까 and -기 때문에 first. Example: 비가 와서 집에 있어요. (biga waseo jibe isseoyo.) "Because it rains, I stay home." See Cause and Reason for the full set.

Conditions (If)

This group has 10 patterns from A2 to B2. It covers "if" and "only if", with -(으)면 first, and it adds hypothetical, contrary and "the more ..." forms. Example: 비가 오면 집에 있을 거예요. (biga omyeon jibe isseul geoyeyo.) "If it rains, I will stay home." Spoken [비가 오면 지베 이쓸꺼예요]. See Conditions (If) for the full set.

Time and Sequence

This is the largest group, with 19 patterns from A1 to C1. It covers "when", "before", "after", "while" and "as soon as", with -(으)ㄹ 때, -기 전에 and -(으)ㄴ 후에 at the start. Example: 밥을 먹기 전에 손을 씻어요. (babeul meokgi jeone soneul ssiseoyo.) "I wash my hands before I eat." Spoken [바블 먹끼 저네 소늘 씨서요]. See Time and Sequence for the full set.

Purpose and Intention

This is the smallest group, with 6 patterns from A1 to B2. It covers "in order to" and "so that", with -(으)러 and -(으)려고 first. Example: 한국어를 배우러 서울에 가요. (hangugeoreul baeureo seoure gayo.) "I go to Seoul to learn Korean." Spoken [한구거를 배우러 서우레 가요]. See Purpose and Intention for the full set.

Contrast and Concession

This group has 14 patterns from A2 to C1. It covers "even if", "even though" and "whereas", with -아/어도 first, and most of its patterns sit at B2 and C1. Example: 비가 와도 가요. (biga wado gayo.) "I go even if it rains." See Contrast and Concession for the full set.

How Do You Choose between Look-Alike Patterns?

Choose by checking three things: the meaning, the tense and the sentence type that follows. Many patterns translate into the same English word, but they differ in what they allow.

The commonest trap is "because". -아/어서 and -(으)니까 both mean "because", and they follow different rules.

The second sentence says "Since it's raining, please stay home" [비가 오니까 지베 계세요]. It is a request, which -아/어서 cannot lead into.

Tense is the next check. In -고 and -거나 sentences, the tense normally goes only on the final verb: 먹고 갔어요 means "ate and went". Other patterns follow their own rules, and each lesson states them.

The third check is spoken versus written style. Several patterns have a written partner:

When two patterns still look alike, the comparison pages give a deciding rule. They include -고 vs -아/어서, -(으)면서 vs -고, -거나 vs -든지, -는데 vs -지만, -다가 vs -(으)면서, -고 나서 vs -(으)ㄴ 후에 and -아/어도 vs -더라도. The whole collection is on Confusing Grammar Compared. The next section suggests how to practise.

Where Can You Practise These Patterns?

Practise each pattern in the lesson that teaches it, then in the comparison page if it has a look-alike. Every lesson has audio for its examples, a sentence-building exercise and a short practice set with answers. A routine that works is:

1. Read one lesson and play every audio example.
2. Rebuild the main example with the sentence builder, then write one sentence of your own.
3. Do the practice set, then read the comparison page for the closest look-alike.
4. A week later, redo the practice set from memory.

The Beginner Grammar list shows which patterns to work on at each level. The next section states what this section leaves out.

What Does This Section Not Cover?

This section covers the endings that link clauses. It does not cover the particles that join nouns, such as 와/과, (이)랑 and (이)나; those are taught in Korean Particles. It also does not cover tense endings (Korean Tenses), speech levels (Korean Speech Levels) or sentence-final endings such as -네요 (Korean Sentence Endings). The wider area is described in Korean Grammar.

In short, Korean connectors give the language its "and", "but", "because", "if", "when", "in order to" and "even if", and the 74 patterns above are sorted by those meanings.

Frequently Asked Questions

Which pattern should I learn first? Start with -고 ("and", A1). Then add the A1 time patterns -(으)ㄹ 때, -기 전에 and -(으)ㄴ 후에, the purpose pattern -(으)러, and the A2 core: -아/어서, -(으)면, -지만 and -(으)ㄴ/는데. Learn the B1 and B2 patterns after those basics feel automatic in speech.

How do I know which pattern fits my sentence? Ask what the first clause does for the second: adds to it (and), contrasts with it (but), causes it (because), sets a condition (if), gives a time (when, before, after), states a purpose (in order to) or concedes a point (even if). Then use the matching group on this page and check the level.

Are these patterns on the TOPIK exam? Most beginner and intermediate connectors appear in TOPIK reading and listening texts, but the official TOPIK site (topik.go.kr) publishes level descriptions, not a pattern-by-pattern list. The levels here are editorial estimates: A1 and A2 patterns match TOPIK I, and B1 and above match TOPIK II. Treat them as a study order, not an official syllabus.

Where are the comparison pages? The most confusable pairs have their own pages: -고 vs -아/어서, -(으)면서 vs -고, -거나 vs -든지, -는데 vs -지만, -다가 vs -(으)면서, -고 나서 vs -(으)ㄴ 후에 and -아/어도 vs -더라도. They are listed on the Confusing Grammar Compared hub, with a deciding rule on each page.

Are connectors formal or casual? Most connectors work in both speech and writing, and the register depends on the pattern. -고, -아/어서 and -지만 are neutral. Written partners are more formal: -(으)며 for -고, -(으)나 for -지만 and -(으)므로 for -아/어서 or -(으)니까. The polite or casual feel comes from the final ending, not the connector.