Politeness strategies play a crucial role in maintaining social harmony and establishing interpersonal relationships. The interpersonal function of language in Systemic Functional Grammar (SFG) provides a framework to analyze how language is used to interact with others. Our research aims to analyze the interpersonal functions of politeness strategies in conversation from the perspective of mood, modality, and person in SFG, with a focus on politeness theory, face theory, and politeness strategies. It shows how language is used to manage social relationships and establish social hierarchies in communication, and how understanding politeness strategies can help communicate more effectively and respectfully in different contexts.