The word "赶快" is formed through the conceptual fusion of its two component characters: "赶" (gǎn), which carries the core idea of rushing or hastening to do something, and "快" (kuài), which means fast or quick. They are combined not merely additively, but interactively, where "赶" provides the context of urgent action and "快" intensifies the required speed and immediacy of that action. The result is a single, unified concept that encapsulates the idea of acting with promptness and hurried diligence, where the sense of haste from the first character is qualitatively defined and amplified by the swiftness of the second.