This paper investigates the syntax and semantics of right dislocation constructions (RDCs) in Korean, with special focus on asymmetries between postverbal arguments and postverbal adjuncts. I argue that RDCs are sub-divided into two types: argument RDCs vs. adjunct RDCs. I propose that postverbal arguments undergo focus movement to the root C in a mono-clausal structure, whereas postverbal adjuncts are base-generated at the end of the utterance, and the head of the adjunct may undergo sideward movement onto the host clause. I show that under the current proposal, we can explain a variety of unique properties of RDCs in Korean, which include: root effects, scope, variability in island effects, Negative Polarity Item (NPI) licensing, wh-licensing, and the presence or absence of LBC and CED effects. My proposal also captures otherwise surprising similarities between argument RDCs and specificational focus constructions and a parallelism between adjunct RDCs and parasitic gap constructions.