The word 力气 is formed by combining two conceptual building blocks: 力, which represents the idea of physical strength, muscular force, or power, and 气, which represents the vital energy, breath, or life force that animates and empowers action. They are joined not grammatically, but semantically, to create a single, unified concept where the raw, tangible capacity for work (力) is fused with the essential, animating energy (气) that makes its application possible, resulting in the comprehensive idea of "strength" or "effort" as a holistic physical capability.