The corpus-driven studyexplores the functional spectrum of the Turkish pragmatic marker ya. Including functional, syntactic and collocational discussions, it reveals that ya often functions in the interpersonal domain, reflecting the speaker's usually negative affective stance. The study indicates that ya acts as a reminder of shared knowledge to avoid communication glitches. In the textual/sequential domain, ya is used as a topic initiator, shifter and expander. Its longer form, yaa has an idiosyncratic summative function, signalling topic termination after the speaker has satisfactorily enlightened an issue. At the utterance-medial position, ya marks the preceding segment as a reason clause, often reflecting unfavourable attitudes. In appeal intonation, ya sounds like a marker of hastener for requests to negotiate desired actions. As an emotional response token it reflects negative attitudes like annoyance, dismay, impatience or disbelief. Marginally, ya is an assertive marker allied to condemnatory wh-questions to criticise someone or functions as a tag question for negative anchors. It was also found that ya forms several collocation patterns that disambiguate some pragmatic functions.