Korean Pattern ~(으)ㄹ 줄 알다/모르다: How to Say "know how to / don't know how to"

Verb stem + (으)ㄹ 줄 알다/모르다. Ability through learned skill, different from ~(으)ㄹ 수 있다 (general ability).

The Rule

~(으)ㄹ 줄 알다/모르다 = "know how to / don't know how to" Verb stem + (으)ㄹ 줄 알다/모르다. Ability through learned skill, different from ~(으)ㄹ 수 있다 (general ability). This is one of the essential Korean grammar patterns. Mastering it unlocks the ability to express "know how to / don't know how to" naturally in conversation — something you'll need almost every day.

Why English Speakers Get It Wrong

In English, "know how to / don't know how to" is expressed with separate words (auxiliary verbs, modals). In Korean, ~(으)ㄹ 줄 알다/모르다 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 + (으)ㄹ 줄 알다/모르다 Verb stem + (으)ㄹ 줄 알다/모르다. Ability through learned skill, different from ~(으)ㄹ 수 있다 (general ability). Step by step: 1. Take any verb (e.g., 가다 = to go) 2. Remove 다 to get the stem (가) 3. Add the pattern: 가으ㄹ 줄 알다/모르다 This works with virtually any Korean verb.

Real Examples

• 수영할 줄 알아요. (suyeonghar jur arayo.) — "I know how to swim." • 운전할 줄 몰라요. (unjeonhar jur morrayo.) — "I don't know how to drive."

Common Mistakes

❌ Trying to translate "know how to / don't know how to" word-by-word from English ✅ Use the pattern ~(으)ㄹ 줄 알다/모르다 attached to the verb stem → Korean expresses "know how to / don't know how 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 → Pay attention to the verb stem's final sound when attaching the pattern.

Quick Tip

Practice ~(으)ㄹ 줄 알다/모르다 with 5 verbs you already know. Write them out: • 가다 (go) → 가으ㄹ 줄 알다/모르다 • 먹다 (eat) → 먹으ㄹ 줄 알다/모르다 Repetition with familiar verbs builds the pattern into muscle memory. Once automatic, you can use it with ANY verb.

~(으)ㄹ 줄 알다/모르다 = "know how to / don't know how to"

Examples

수영할 줄 알아요. — suyeonghar jur arayo. — I know how to swim.

운전할 줄 몰라요. — unjeonhar jur morrayo. — I don't know how to drive.