Adopting the interactional linguistic framework, the study aimed at exploring the range and frequency of interactional functions of yes/no tokens used by Thai university students of A2 proficiency in their English conversation, and contrasting their use with that of English native speakers (ENSs). The data was derived from 83, two-three party role-play conversations of approximately three--five minutes long obtained from conversation classes that were transcribed and analyzed. The findings revealed the students' use of yes tokens in the following order of functional frequency: acceptance, confirmative response, positive alignment, acknowledgment, topic shift and self-confirmation. By contrast, no tokens were employed most often to disconfirm/disagree, followed by doing disappointment, restatement and negative alignment. Additionally, the students appeared to overuse yes tokens to fulfill certain functions for which ENSs usually deployed other expressions, and had difficulty giving grammatical short answers with the tokens. Furthermore, unlike ENSs, they often used these tokens alone, repeatedly or redundantly with other expressions of the same functions. It was suggested that students be made aware of grammatical expressions that can co-occur with yes/no tokens in giving short answers, and especially of a wider range of expressions commonly used in a specific context and various contexts in which an expression can be appropriately used.