Reviewing the Three Rules
Before conjugating a new word, always start by dropping -다 from the dictionary form to find the stem.
Then, look at the ending you want to attach. In Korean, endings follow one of three main rules:
Rule 1: Endings that just attach directly.
Rule 2: Endings that require you to choose between 아 or 어 .
Rule 3: Endings that require you to check for a batchim (bottom consonant).
Core takeaway: Drop -다
Rule 1: Endings That Just Attach
Some endings, like -고 (and) and -지만 (but), are very simple. They do not care about the vowels or consonants in the stem.
Just drop -다 and attach the ending directly.
Dictionary Form · -고 · -지만
타다 · 타고 · 타지만
마시다 · 마시고 · 마시지만
닫다 · 닫고 · 닫지만
Core takeaway: -고 and -지만
Rule 2: Choosing 아 or 어
Endings like -아요/-어요 (present) and -았어요/-었어요 (past) require you to check the stem's last vowel.
If the last vowel is ㅏ or ㅗ , choose the 아 form.
For all other vowels, choose the 어 form.
Remember that vowels often blend together, and the vowel ㅡ drops when it meets these endings.
Dictionary Form · Present (-아요/-어요) · Past (-았어요/-었어요)
닫다 (has ㅏ) · 닫아요 · 닫았어요
마시다 · 마셔요 · 마셨어요
바쁘다 (ㅡ drops) · 바빠요 · 바빴어요
Core takeaway: Check last vowel
Rule 3: Checking for a Batchim
Endings that start with (으) , such as -(으)면 (if), -(으)세요 (please), and -(으)ㄹ 거예요 (future), need to know if the stem ends in a consonant.
No batchim: Attach the ending directly (e.g., -면, -세요, -ㄹ 거예요).
Has batchim: Add the cushion vowel 으 first (e.g., -으면, -으세요, -을 거예요).
Dictionary Form · -(으)면 · -(으)세요
타다 · 타면 · 타세요
신다 · 신으면 · 신으세요
Core takeaway: No batchim = attach directly
A Quick Look at Irregulars
Using these three rules, you can conjugate most Korean verbs and adjectives. However, you will sometimes encounter words that seem to break these patterns.
For example, 듣다 (to listen) becomes 들어요 , and 춥다 (to be cold) becomes 추워요 . The stem itself changes before the ending is attached.
These are called irregular verbs . You do not need to memorize them right now. Just remember that if a word's stem changes completely, it might be an irregular verb, which we will explore in the next course!
Quick review
Some stems change completely
called irregulars
covered in next course