Before you read a single table in this reference, learn the one machine that generates all of them. Every conjugated Korean predicate — every 먹어요, 갔습니다, 살면, 좋았어 — is built the same way: stem + ending. Master that, and the hundreds of forms in these tables stop being things to memorize and become things you can predict. This page builds the machine; the rest of the reference is just an inventory of endings to slot into it.
The dictionary form ends in -다; strip it for the stem
Every Korean verb and adjective is cited in a form ending in -다: 먹다 ("to eat"), 가다 ("to go"), 좋다 ("to be good"), 하다 ("to do"). That -다 is a naming label, not a usable sentence — the equivalent of English "to eat," which you would never say in place of "I eat." Remove it and what is left is the stem (어간), the fixed core that carries the meaning:
| Dictionary form | Meaning | Stem | Ends in… |
|---|---|---|---|
| 먹다 | to eat | 먹- | batchim ㄱ (consonant) |
| 가다 | to go | 가- | vowel ㅏ |
| 좋다 | to be good | 좋- | batchim ㅎ (consonant) |
| 하다 | to do | 하- | vowel ㅏ (special: → 해) |
The stem never changes. This is the payoff for an English speaker: where English fuses and mutates its verbs (go / went / gone, be / is / was — separate memorized words), Korean keeps 먹- as 먹- through the present, the past, the future, the polite, and the casual. You only ever change what you hang off the end.
Three factors decide the ending's shape
An ending is not one fixed string; most endings have two or three skins, and exactly three factors choose which skin appears. Every table in this reference is organized around these three.
Factor 1 — batchim (final consonant) or vowel? Look at the last letter of the stem. If it ends in a 받침 (a bottom consonant, like the ㄱ of 먹-), a family of endings inserts a buffer vowel 으, and the formal ending is -습니다. If it ends in a vowel (like 가-), the 으 is dropped and the formal ending is -ㅂ니다.
여기 앉으세요.
yeogi anjeuseyo
Please sit here. (consonant stem 앉- inserts the 으 buffer)
안녕히 가세요.
annyeonghi gaseyo
Goodbye — said to someone leaving. (vowel stem 가- takes no 으)
Factor 2 — ㅏ/ㅗ vowel harmony. For the huge -아/어 family of endings (the polite -아/어요, the past -았/었-, the connective -아/어서), the ending's vowel is chosen by the stem's last vowel. If that vowel is ㅏ or ㅗ, the ending takes 아; otherwise it takes 어. The verb 하- is a law unto itself: 하 + 여 fuses to 해.
창문 좀 닫아 주세요.
changmun jom dada juseyo
Please close the window. (닫- has ㅏ → takes 아: 닫아)
지금 밥 먹어요.
jigeum bap meogeoyo
I'm eating now. (먹- has ㅓ, not ㅏ/ㅗ → takes 어: 먹어)
저는 매일 운동해요.
jeoneun maeil undonghaeyo
I exercise every day. (하- → 해)
Factor 3 — is the stem irregular? A handful of stem types (the ㅂ, ㄷ, ㅅ, 르, 으, ㅎ classes) mutate before certain endings — 춥다 → 추워요, 듣다 → 들어요. These live in the partner irregular reference; everything on the regular paradigm pages assumes a non-mutating stem. If a form ever looks "off," suspect Factor 3.
Three worked joins
Watch the machine run. Each of these is just stem + ending, with one factor doing the work:
- 먹 + 어요 → 먹어요. The stem vowel ㅓ is not ㅏ/ㅗ, so harmony (Factor 2) selects 어. The ㄱ liaises onto the following vowel in speech: [머거요].
- 가 + 아요 → 가요. Harmony selects 아 (stem vowel ㅏ), but two identical ㅏ vowels contract into one — you never say ×가아요.
- 좋 + 아요 → 좋아요. Stem vowel ㅗ selects 아; the batchim ㅎ goes silent between vowels, so it is pronounced [조아요].
오늘 점심 뭐 먹어요?
oneul jeomsim mwo meogeoyo?
What are you having for lunch today?
저 지금 학교에 가요.
jeo jigeum hakgyo-e gayo
I'm heading to school right now.
날씨가 정말 좋아요.
nalssiga jeongmal joayo
The weather is really nice.
Notice that 좋다 — an adjective in English terms — runs through the identical machine as 가다. Korean adjectives are a species of verb (descriptive verbs), so the same endings apply. That one fact reorganizes a lot of English intuition; see action vs descriptive verbs.
Endings stack in a fixed order
The real economy shows when you stack. Tense goes on first, politeness last, and each layer stays legible. Read 먹었어요 left to right and you can see the seams: 먹 (eat) + 었 (past) + 어요 (polite).
| Stem |
|
| Result |
|---|---|---|---|
| 먹- | -었- (past) | -어요 | 먹었어요 |
| 가- | -았- (past) | -아요 | 갔어요 |
| 하- | -였-→했 (past) | -어요 | 했어요 |
벌써 밥 먹었어요?
beolsseo bap meogeosseoyo?
Have you eaten already?
어제 부산에 갔어요.
eoje Busane gasseoyo
I went to Busan yesterday.
Nothing here fuses beyond recognition. Peel off -어요 and the past marker -었- is sitting right there; peel that off and you are back at the bare stem. This transparency is why the tables in this reference are worth internalizing as endings, not as word lists.
Why this is easier than English, once you see it
Coming from English, the reflex is to treat each conjugated form as a fresh vocabulary item to be memorized. Fight that reflex. Korean rewards the opposite: learn the endings as a small closed set, learn to read a stem's last letter and last vowel, and every one of the language's thousands of verbs falls out automatically. Went, gone, going, goes are four unpredictable English shapes; Korean gives you one stem plus a handful of stackable, meaning-transparent suffixes that behave the same on every regular verb. The endings are the curriculum. The stems just plug in.
Common Mistakes
1. Speaking the dictionary form. -다 is a citation label, not "I do X." A real utterance needs a real ending.
❌ 저는 학교에 가다.
Wrong — 가다 is the naming form; it cannot be a spoken sentence.
✅ 저는 학교에 가요.
jeoneun hakgyo-e gayo
I go to school.
2. Choosing the harmony vowel by the wrong syllable. Harmony looks at the stem's last vowel, not the first.
❌ 오늘 도서관에서 책을 읽아요.
Wrong — 읽- has ㅣ (not ㅏ/ㅗ), so it takes 어: 읽어요.
✅ 오늘 도서관에서 책을 읽어요.
oneul doseogwaneseo chaegeul ilgeoyo
I'm reading a book at the library today.
3. Forgetting the 으 buffer on a consonant stem. Before -(으) endings, a batchim stem inserts 으.
❌ 이 책 좀 읽세요.
Wrong — consonant stem 읽- needs the buffer: 읽으세요.
✅ 이 책 좀 읽으세요.
i chaek jom ilgeuseyo
Please read this book.
4. Treating 하다 like a normal ㅏ-stem. 하- does not take 아; it fuses to 해.
❌ 저는 매일 공부하아요.
Wrong — 하- becomes 해, never 하아: 공부해요.
✅ 저는 매일 공부해요.
jeoneun maeil gongbuhaeyo
I study every day.
Key Takeaways
- Every predicate is stem + ending; strip -다 to get the stem (먹다 → 먹-), which never changes.
- Three factors shape each ending: (1) batchim vs vowel (으 buffer, -습니다 vs -ㅂ니다); (2) ㅏ/ㅗ harmony (아 vs 어, 하 → 해); (3) irregular class (its own tables).
- Endings stack in order — tense before politeness (먹 + 었 + 어요) — and stay legible.
- Learn the endings, not whole forms: one ending unlocks thousands of verbs, unlike English's memorized go / went / gone.
Now practice Korean
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Korean→Related Topics
- How to Read the Tables in This ReferenceTOPIK 1 — The fixed conventions every paradigm table uses — rows are tenses and moods, columns are the four speech levels, and the notation -(으), 아/어, and a leading dash all mean specific things — so you can look any verb up in three moves.
- The 아/어 Vowel-Harmony Selection TableTOPIK 1 — The master lookup sheet for choosing 아 vs 어 in every harmony-sensitive ending: if the stem's last vowel is ㅏ or ㅗ, use 아; for everything else use 어; 하 alone takes 여 → 해.
- The -(으) Insertion Table: When 으 AppearsTOPIK 1 — The linking vowel -(으)- surfaces only between a consonant-final stem and a set of endings, is absent after a vowel stem, and disappears in ㄹ-stems (which drop the ㄹ instead) — laid out ending by ending across all three stem types.
- 먹다 (to eat): Consonant-Stem Verb ParadigmTOPIK 1 — The complete look-up paradigm of 먹다 across all four speech levels — the stencil for every regular consonant-stem action verb, with the obligatory 으 buffer that batchim stems insert before consonant-initial endings.
- Verb Stems and Endings: How Korean Conjugation WorksTOPIK 1 — Every Korean verb and adjective is cited in a -다 form; strip the -다 and the STEM is what remains — all conjugation is just attaching stacked endings to that stem, with one vowel-vs-consonant distinction (으-insertion) governing almost every choice.