The word 正在 is formed by combining two separate characters, each contributing a sense of immediate presence and continuity. The character 正 conveys the idea of being upright, correct, or directly in the middle of an action, while 在 fundamentally means "to be at" or "to exist in" a specific state or location. When fused, they create a composite concept where 正 intensifies the immediacy and 在 provides the sense of ongoing existence, resulting in a unified expression that emphasizes an action being directly and presently in progress at this very moment.