Mandarin sentence-final particles (SFPs) play a critical role in interpersonal communication, conveying speakers’ intentions and emotions without altering the propositional truth value. Despite their linguistic significance, existing research often relies on subjective analysis and lacks empirical evidence. Furthermore, while SFP comprehension has been linked to emotional regulation and adaptability, the relationship between SFP usage and mentalizing ability remains unexplored. This study investigates how mentalizing ability influences SFP choices across generations and genders. An oral discourse task with 80 participants revealed that women with higher empathy frequently used -ba in other-oriented contexts, reflecting greater sensitivity to interpersonal dynamics. In contrast, middle-aged men with alexithymic tendencies preferred -ya, reflecting reduced emotional engagement. The findings connect SFP usage to psychological traits like empathy and alexithymia, highlighting SFPs’ role in interpersonal relationships and their cognitive underpinnings.