Connective Endings 연결어미: How Korean Joins Clauses

English joins two ideas with a little bridge-word sitting between two finished sentences: "I eat and I sleep," "it's raining but I'll go." Korean does something structurally different and, once it clicks, far more elegant: it fuses the link straight into the first verb's ending and leaves that verb deliberately unfinished. The word that carries "and / but / because" isn't a separate conjunction — it's a suffix called a 연결어미 (connective ending) glued onto the verb stem. This page is the map of that system: how the architecture works, and why it means only the last verb in your sentence gets tense and politeness.

The architecture: leave the first verb unfinished

Look at three sentences, each linking two clauses. The connective ending is bolded — notice it's part of the verb, with nothing standing between the clauses:

In 먹고, 오지만, 고파서, the first verb stops at the connective ending. It does not become 먹어요, 와요, or 고파요 first — the ending attaches to the bare stem (먹-, 오-, 고파-) and the verb is left hanging, waiting for the rest of the sentence. The connective is the "and / but / because." There is no separate word for it.

The link is an ending, not a floating word

This is the single hardest thing for English speakers to internalize, because English trains you to hunt for the word that means "and." In Korean there is no such standalone word inside a sentence — the relationship is morphology. Swap the ending and you swap the relationship, all on the same verb stem:

Only the last verb is "finished"

Because the non-final verb stops at the connective, it carries no tense and no speech level. All of that lands on the final verb — the one that actually ends the sentence. This is the payoff of the architecture, and it's why Korean sentences feel like they build toward a single finishing verb.

Watch tense appear only at the end. The event is entirely in the past, yet 먹고 stays tenseless — 잤어요 does all the work:

The same is true of politeness. Whether you're being casual or formal, you mark it once, on the final verb — never on the connective:

Compare 먹어요 (polite) and 먹습니다 (formal) at the end above: 씻고 didn't change at all. The connective clause is register-neutral; the last verb sets the tone for the whole sentence.

One English word, several Korean endings

Here's a preview of why the next pages exist. Because these links are grammaticalized endings rather than loose words, English's blunt three-way "and / but / because" fans out into a whole family of Korean endings, each with its own shade and its own rules. "Because" alone splits at least three ways:

• -아/어서 — cause tightly bound to result (배고파서 먹었어요)
• -(으)니까 — reason offered to the listener, and the only one that allows a following command (see -(으)니까)
• -기 때문에 — a heavier, more written "because" (see -기 때문에)

They are not interchangeable. Each one restricts what tense it allows on itself, whether the two clauses may have different subjects, and whether a command or suggestion can follow — the subject of the three constraints. For now, just absorb the big idea: choosing a connective ending is choosing a relationship plus a set of rules, not just translating a conjunction.

연결어미 vs. sentence-initial adverbs (그리고, 그래서)

Korean does have words like English "and" and "so" — but they live at the start of a new sentence, after a full stop, not inside one clause. 그리고 ("and then"), 그래서 ("so"), 하지만 ("but") are conjunctive adverbs: they do the same jobs as the connective endings, but across a period rather than within a verb.

So the same two ideas have two natural packagings: fuse them with a connective ending inside one sentence (밥을 먹고 자요), or split them into two sentences bridged by an adverb (밥을 먹어요. 그리고 자요). Both are correct — but in flowing speech and writing the fused version is usually tighter and more native. Reaching for 그리고 in the middle of a single intended sentence is the giveaway of an English-shaped Korean sentence. The full set of these sentence-openers lives in the Conjunctions group; this Connective Endings group is about the endings that do the job inside the clause.

Common Mistakes

1. Gluing two finished 요-clauses with 그리고 instead of fusing -고. Inside one sentence, use the ending.

2. Attaching the connective to the polite 요-form instead of the stem. Connectives glue to the bare stem.

3. Ending a sentence on the connective clause. The connective leaves the verb unfinished; the sentence still needs a finished final verb.

Key Takeaways

• Korean joins clauses with a 연결어미 — an ending fused onto the first verb's stem — not with a separate conjunction word sitting between two finished sentences.
• The non-final verb is left unfinished; tense and speech level land only on the final verb (밥을 먹고 잤어요).
• Swapping the ending swaps the relationship: 먹고 (and), 먹지만 (but), 먹어서 (so).
• One English conjunction maps to several Korean endings — three "because"s alone — each with its own constraints, covered next.
• Sentence-initial adverbs (그리고, 그래서, 하지만) do the same jobs across a full stop; don't drop them into the middle of a single sentence where an ending belongs.