먼저(meon-jeo, meonjeo)
An adverb indicating order or priority
When to use
Emphasizing order, Expressing priority, Guiding procedure
The nuance
Used when an action or event occurs before or takes priority over another. Focuses on order, procedure, or priority rather than strictly on time.
일찍(il-jjik, iljjik)
An adverb indicating an earlier time than usual or others
When to use
Temporal precedence, Daily time expression, Time appointments
The nuance
Used to indicate being earlier in time than usual or others. Focuses on temporal precedence rather than order.