Abstract: As a conventional coordinating conjunction, and is capable of combining clauses to create conditional clause complexes that convey both a conditional and an imperative meaning.Drawing on the theoretical framework of systemic functional linguistics, this paper endeavors to investigate the double meaning of conditional-and clause complexes and the language mechanism from an interpersonal metaphor perspective.The study finds that by leveraging mood and appraisal metaphors, conditional-and clause complexes allow for the blending of the conditional-result logical meaning with the interpersonal meaning of a command or an appraisal.In doing so, speakers can modulate (i.e., enhance or soften) their directive force, or indirectly convey attitudes, stances and other interpersonal evaluations of specified things or events, thus expanding the meaning potential of the language system.