Formal Connective Endings in Korean

In Brief

Korean can connect clauses by attaching an ending directly to the first verb or descriptive verb: -(으)므로 gives a formal reason, -(으)나 marks formal contrast, -거나 presents alternatives, and -(으)며 formally adds information or means “while.” The first, second, and fourth forms are especially common in reports, notices, presentations, and careful writing; -거나 is neutral enough for ordinary conversation too.

Overview

A connective ending is an ending attached to a predicate—the verb or descriptive verb that completes a Korean clause—to link that clause with what follows. English usually places a separate conjunction such as “because,” “but,” “or,” or “while” between clauses. Korean commonly puts that relationship on the first predicate instead: 시간이 없으므로 생략합니다 joins 시간이 없다 (“there is no time”) to 생략합니다 (“I will omit it”).

At B2, the challenge is not simply learning four new translations. It is choosing a form that suits the relationship and the register (the level and style of language appropriate to a situation). -아/어서, -지만, -고, and -(으)면서 are normal in everyday speech. -(으)므로, -(으)나, and additive -(으)며 often create the measured tone found in instructions, applications, reports, academic prose, news, and formal presentations.

These endings do not determine the final speech level. The last predicate still carries the sentence-final ending: 좋다, 좋아요, or 좋습니다. A formal connective often appears with -습니다, but it can connect to another ending when the context calls for it.

How It Works

Remove -다 from the dictionary form to find the stem: 가다 → 가-, 먹다 → 먹-, 좋다 → 좋-. Then attach the connective to that stem. Tense and honorific markers may come before the connective: 발표했으나 (“announced, but”), 참석하시므로 (“because [an honored person] attends”).

The four core meanings

Ending	Main relationship	Typical English rendering	Typical register
-(으)므로	reason or basis	because, since, given that	formal and written
-(으)나	contrast or concession	but, although, while	formal, literary, or written
-거나	alternative	or, either … or	neutral; spoken and written
-(으)며	addition or simultaneous action	and, as well as, while	often formal when additive; also used for simultaneous action

An English translation is only a guide. Ask what logical relationship the Korean sentence expresses, then consider whether the setting is conversational or formal.

-(으)므로: a formal reason

Attach -므로 after a vowel-ending stem and generally after a stem ending in ㄹ; attach -으므로 after another final consonant.

Stem type	Formation	Example
vowel	stem + -므로	가다 → 가므로
final ㄹ	stem + -므로	멀다 → 멀므로
other final consonant	stem + -으므로	먹다 → 먹으므로
이다	이므로	학생이다 → 학생이므로
past marker	past form + -으므로	끝났다 → 끝났으므로

-(으)므로 presents the first clause as an objective reason, basis, or justification for the second. It is stronger and more impersonal than the very common -아/어서. Compare:

• 길이 막혀서 늦었어요. — “I was late because traffic was bad.” Natural conversation.
• 도로가 혼잡하므로 대중교통을 이용하시기 바랍니다. — “As the roads are congested, please use public transportation.” Public-information style.

The ending itself does not mean “therefore.” The result follows in the next clause. A sentence may also end in -(으)므로 when the rest is deliberately left understood, but that is marked and context-dependent rather than the basic pattern.

-(으)나: formal contrast

Attach -나 after a vowel. Attach -으나 after most consonants. With a stem ending in ㄹ, the ㄹ normally drops before -나: 알다 → 아나, 멀다 → 머나. In practice, learners often meet the form in transparent examples such as 가나, 먹으나, 했으나, and 있으나.

Stem type	Formation	Example
vowel	stem + -나	비싸다 → 비싸나
other final consonant	stem + -으나	좋다 → 좋으나
final ㄹ	drop ㄹ + -나	멀다 → 머나
이다	이나	학생이다 → 학생이나
past marker	past form + -으나	검토했다 → 검토했으나

The first clause sets up a fact or expectation, and the second clause contrasts with it: 가격은 비싸나 품질은 좋습니다. In speech, -지만 is usually more natural: 비싸지만 품질이 좋아요. Do not use -(으)나 merely to make every sentence sound more advanced; in a casual chat it may sound stiff, literary, or deliberately dramatic.

-거나: alternatives

-거나 attaches directly to any verb or descriptive-verb stem; there is no 으 variant: 가거나, 먹거나, 좋거나, 멀거나. It can also follow tense marking: 갔거나, 먹었거나.

Use it between predicates when either action, state, or possibility can apply:

• 걷거나 뛰세요. — “Walk or run.”
• 주말에는 책을 읽거나 영화를 봐요. — “On weekends I read a book or watch a movie.”

For alternatives between nouns, Korean normally uses (이)나, not -거나: 차나 커피 (“tea or coffee”). A longer pattern, -거나 … -거나, explicitly lists alternatives: 직접 방문하거나 이메일로 신청하거나 하세요 (“Either visit in person or apply by email”). In natural Korean, only the first predicate often needs -거나, with the final alternative carrying the sentence ending.

-(으)며: addition and simultaneous action

Attach -며 after a vowel or a stem ending in ㄹ, and -으며 after another consonant.

Stem type	Formation	Example
vowel	stem + -며	일하다 → 일하며
final ㄹ	stem + -며	살다 → 살며
other final consonant	stem + -으며	웃다 → 웃으며
이다	이며	학생이다 → 학생이며
past marker	past form + -으며	증가했다 → 증가했으며

This ending has two closely related uses:

1. Formal addition: 이 제품은 가벼우며 내구성이 뛰어납니다. (“This product is light and highly durable.”) It organizes parallel facts, much like formal English “and” or “as well as.”
2. Simultaneous action: 웃으며 말했어요. (“[They] spoke while smiling.”) Here the two actions happen together, often with the same subject.

For simultaneous actions, -(으)면서 is more explicit and more common in conversation: 음악을 들으면서 공부해요. -(으)며 is shorter and can sound more written, though forms such as 웃으며, 울며, and 노래하며 also occur naturally in narrative or polished speech.

Negation, tense, and sentence endings

Negation belongs inside the connected clause: 필요하지 않으므로 (“because it is not necessary”), 동의하지 않으나 (“although [someone] does not agree”), 먹지 않거나 (“or not eat”), and 쉬지 않으며 (“without resting / and does not rest”).

Past marking normally comes before the connective:

Structure	Example	Meaning
stem + past + reason	늦었으므로	because [someone] was late
stem + past + contrast	신청했으나	applied, but / although [someone] applied
stem + past + alternative	갔거나	went or / may have gone
stem + past + addition	확인했으며	checked and / also confirmed

The final clause controls the overall ending: 취소합니다 is formal, 취소해요 is polite conversational, and 취소했다 is plain written style.

Examples in Context

Korean	English	Note
시간이 없으므로 생략합니다.	I will omit it because there is no time.	Formal reason
안전 점검 중이므로 출입을 금합니다.	Entry is prohibited because a safety inspection is in progress.	Public notice
서류가 미비하므로 다시 제출해 주십시오.	Since the documents are incomplete, please submit them again.	Formal request based on a reason
가격은 비싸나 품질이 좋습니다.	It is expensive, but the quality is good.	Written contrast
여러 차례 연락했으나 답변을 받지 못했습니다.	I contacted them several times but did not receive a reply.	Past contrast
규모는 작으나 영향력은 큽니다.	Although its scale is small, its influence is considerable.	Contrasting qualities
걷거나 뛰세요.	Walk or run.	Alternative actions
주말에는 집에서 쉬거나 친구를 만나요.	On weekends, I rest at home or meet friends.	Everyday use of -거나
신청서는 온라인으로 내거나 우편으로 보내면 됩니다.	You can submit the application online or send it by mail.	Two possible methods
비가 오거나 눈이 오면 행사가 취소됩니다.	If it rains or snows, the event will be canceled.	Alternative conditions
웃으며 말했어요.	They spoke while smiling.	Simultaneous action
이 도시는 교통이 편리하며 문화 시설도 많습니다.	This city has convenient transportation and many cultural facilities.	Formal addition
그는 연구자이며 대학에서 강의도 합니다.	He is a researcher and also teaches at a university.	이다 → 이며
자료를 검토했으며 결과는 내일 발표하겠습니다.	We reviewed the materials, and we will announce the results tomorrow.	Report or presentation style

Common Mistakes

Adding 으 after every consonant

• Wrong: 살으므로, 살으며
• Right: 살므로, 살며
• Why: With these two endings, a stem ending in ㄹ takes -므로 or -며, without an extra 으.

Using -거나 between nouns

• Wrong: 커피거나 차를 주세요.
• Right: 커피나 차를 주세요.
• Why: -거나 connects predicates. The noun alternative “coffee or tea” normally uses (이)나.

Treating -(으)며 as an everyday replacement for -고

• Unnatural in a casual routine: 아침을 먹으며 학교에 갔어요 when you mean “I ate breakfast and then went to school.”
• Better: 아침을 먹고 학교에 갔어요.
• Why: -(으)며 can mark simultaneous action or formal addition, not a simple everyday sequence of completed events. Eating breakfast and then leaving is sequential, so -고 fits.

Overusing formal forms in casual conversation

• Stiff with a friend: 오늘 피곤하므로 집에 갈게요.
• Natural: 오늘 피곤해서 집에 갈게요.
• Why: -(으)므로 sounds official or written. Ordinary personal reasons usually take -아/어서 or -(으)니까.

Confusing contrast with alternatives

• Wrong: 비싸거나 품질이 좋아요 when you mean “It is expensive, but the quality is good.”
• Right: 비싸지만 품질이 좋아요 or formal 비싸나 품질이 좋습니다.
• Why: -거나 offers alternatives; -지만 and -(으)나 express contrast.

Usage Notes

-(으)므로 is common where the writer gives a policy basis, explanation, or conclusion: notices, regulations, instructions, and formal correspondence. It can be translated as “because,” but English may prefer “as,” “since,” or “given that” to reflect its impersonal tone. In personal conversation, it can sound as though the speaker is issuing an official justification.

-(으)나 often appears in reports and essays, especially when balancing two facts. It also occurs in elevated narrative. Conversational Korean strongly favors -지만. A useful reading clue is that 있으나, 없으나, 했으나, and 되었으나 frequently introduce an important limitation or unexpected result.

Unlike the other three forms, -거나 is not specifically formal. Its inclusion here is useful because formal documents also need to state alternatives, but you will hear it constantly in daily speech. In negative combinations such as -지 않거나, it may mean “or does not …”; pay attention to the full predicate rather than translating one ending at a time.

With -(으)며, check whether the clauses are parallel facts or simultaneous actions. In the simultaneous reading, the understood subject is normally shared: 민수는 웃으며 대답했다 means Minsu both smiled and answered. If two clearly different subjects perform the actions, a fuller connector or separate clauses are often clearer.

Beyond the Basics / Advanced Use

Formal Korean often chains several -(으)며 clauses before one final predicate: 본 조사는 익명으로 진행되며, 응답 내용은 연구 목적으로만 사용되며, 개인정보는 수집하지 않습니다. This avoids repeating sentence-final endings and creates cohesive administrative or academic prose. Use such chains sparingly: too many connected clauses make a sentence hard to follow.

A writer can combine different connectors to show a logical hierarchy: 수요가 증가했으나 공급이 부족하므로 가격이 상승할 가능성이 있습니다 means “Although demand has increased, prices may rise because supply is insufficient.” Here -으나 marks the background contrast, while -으므로 supplies the direct reason for the prediction. Reading from left to right is not enough; identify which clause each ending connects to.

You may also encounter the fixed-looking written form -므로써, but it must not be confused with -(으)므로. -(으)므로 means “because,” whereas -(으)ㅁ으로써 means “by doing” or “through doing”: 협력함으로써 문제를 해결했다 (“They solved the problem by cooperating”). The noun-forming -(으)ㅁ is part of the latter construction.

In compressed headlines, legal language, and literary prose, the boundaries between “and,” “while,” and “as” may be deliberately broad. Rather than forcing one English conjunction onto every -(으)며, decide whether the first clause adds a parallel fact, describes a concurrent action, or supplies background to the next event.

Practice Tips

1. Rewrite by register. Take four conversational sentences using -아/어서, -지만, -고, and -(으)면서, then rewrite suitable ones with -(으)므로, -(으)나, or -(으)며 as if they appeared in a notice or report. Not every sentence should be converted.
2. Sort real examples by relationship. When reading Korean news, instructions, or institutional websites, mark each connector as reason, contrast, alternative, addition, or simultaneity. This trains meaning before translation.
3. Practice stems in sets. Make short groups with a vowel stem, a ㄹ stem, another consonant stem, and 이다: 가므로/살므로/먹으므로/학생이므로 and 가며/살며/먹으며/학생이며.

Related Concepts

• Prerequisite: Polite Ending -아/어요 — review how the final predicate carries politeness even when earlier clauses use connective endings.
• Next step: Written/Formal Style — develop the broader sentence patterns and conventions used in reports and formal prose.
• Next step: Complex Conjunctions — combine more advanced clause relationships with forms such as -는 데다가 and other multi-part connectors.