Korean Pattern ~아/어야 하다: How to Say "must / have to"

Verb stem + 아/어야 하다. The vowel harmony rule applies: ㅏ/ㅗ → 아야, others → 어야.

The Rule

~아/어야 하다 = "must / have to" Verb stem + 아/어야 하다. The vowel harmony rule applies: ㅏ/ㅗ → 아야, others → 어야. This is one of the essential Korean grammar patterns. Mastering it unlocks the ability to express "must / have to" naturally in conversation — something you'll need almost every day.

Why English Speakers Get It Wrong

In English, "must / have to" is expressed with separate words (auxiliary verbs, modals). In Korean, ~아/어야 하다 is a grammatical ENDING attached to the verb stem. You can't just translate word-by-word. The common mistake: trying to combine Korean words the way English does instead of attaching the pattern to the verb stem. Korean grammar works by stacking endings, not by adding separate helper words.

How It Works

Formation: Verb stem + 아/어야 하다 Verb stem + 아/어야 하다. The vowel harmony rule applies: ㅏ/ㅗ → 아야, others → 어야. Step by step: 1. Take any verb (e.g., 가다 = to go) 2. Remove 다 to get the stem (가) 3. Add the pattern: 가아/어야 하다 This works with virtually any Korean verb.

Real Examples

• 숙제를 해야 해요. (sukjereur haeya haeyo.) — "I have to do homework." • 일찍 일어나야 해요. (irjjik ireonaya haeyo.) — "I have to wake up early."

Common Mistakes

❌ Trying to translate "must / have to" word-by-word from English ✅ Use the pattern ~아/어야 하다 attached to the verb stem → Korean expresses "must / have to" as a single grammatical construction, not separate words. ❌ Forgetting vowel harmony or consonant rules ✅ Check if the verb stem ends in a vowel or consonant — the pattern may change form → Verb stem + 아/어야 하다.

Quick Tip

Practice ~아/어야 하다 with 5 verbs you already know. Write them out: • 가다 (go) → 가아/어야 하다 • 먹다 (eat) → 먹아/어야 하다 Repetition with familiar verbs builds the pattern into muscle memory. Once automatic, you can use it with ANY verb.

~아/어야 하다 = "must / have to"

Examples

숙제를 해야 해요. — sukjereur haeya haeyo. — I have to do homework.

일찍 일어나야 해요. — irjjik ireonaya haeyo. — I have to wake up early.