How to Conjugate 크다 (to be big): regular-vowel Pattern

ㅡ vowel stem: ㅡ drops. No previous vowel → 어요. 크 + 어요 → 커요.

The Rule

ㅡ vowel stem: ㅡ drops. No previous vowel → 어요. 크 + 어요 → 커요. 크다 follows the regular-vowel irregular pattern. This means the verb stem changes when certain endings are added. Don't worry — once you learn this pattern, it applies to many other verbs too.

Why English Speakers Get It Wrong

English verb conjugation is relatively simple — "I eat, he eats, I ate." Korean is more complex because the verb ending changes based on politeness level, tense, AND the verb stem's final vowel or consonant. The regular-vowel pattern is especially tricky because the stem itself changes. English irregular verbs (go→went) change unpredictably, but Korean irregular verbs follow learnable PATTERNS. Once you know the regular-vowel rule, you can predict how all regular-vowel verbs behave.

How It Works

Stem: 크 Polite present (해요체): 커요 Polite past: 컸어요 Polite future: 클 거예요 Formal (합쇼체): 큽니다 Negative: 안 커요 Notice how the stem "크" changes in some forms. This is the regular-vowel pattern in action.

Real Examples

• 커요 (keoyo) — "be big (polite present)" • 컸어요 (keoteoyo) — "be big (past)" • 클 거예요 (keur geoyeyo) — "will be big (future)" • 큽니다 (keupnida) — "be big (formal)" • 안 커요 (an keoyo) — "don't be big"

Common Mistakes

❌ 크어요 (keueoyo) ✅ 커요 (keoyo) → ㅡ drops: 크 + 어요 → 커요. ❌ Using the casual form (크어/아) in formal situations ✅ Use 큽니다 when speaking to elders, at work, or in official settings → Mixing up politeness levels is one of the most noticeable mistakes foreigners make in Korean.

Quick Tip

Start by mastering the 해요체 (polite) form: 커요. This is the form you'll use 90% of the time in daily life. Once it's automatic, add the past (컸어요) and future (클 거예요) to your toolkit. For regular-vowel verbs, make a list of 5 common ones and practice all their forms. The pattern will click after repetition.

크다: 커요 (present) / 컸어요 (past) / 클 거예요 (future)

Examples

커요 — keoyo — be big (polite)

컸어요 — keoteoyo — be big (past)

클 거예요 — keur geoyeyo — will be big

큽니다 — keupnida — be big (formal)

안 커요 — an keoyo — don't be big