Indicates not knowing how to do an action or lacking the ability to do it.
When to use
expressing ability, lack of skill, lack of experience
The nuance
Attach -(으)ㄹ 줄 모르다 to the verb stem to express not knowing how to do that action. Use -을 줄 모르다 if the stem ends with a consonant, -ㄹ 줄 모르다 if it ends with a vowel.
