This dissertation investigates linguistic and metalinguistic practices in everyday Twitter discourse in relation to aspects of speech and writing. The overarching aim is to investigate how the spoken–written interface is reconfigured in the digital writing spaces of social media. The dissertation comprises four empirical case studies and six chapters. The first study investigates communicative functions of hashtags in a speech act pragmatic framework, focalizing tagging practices that not only mark topics or organize hypertextual interaction, but rather have more specific locally meaningful functions. Two studies investigate reported speech in tweets, focusing on quotatives typically associated with informal conversational interaction (e.g., BE like). The studies identify strategies by which Twitter users animate (Tannen, 2007) speech reports. Further, one of the studies explores how such animating practices are afforded (Hutchby, 2001). Lexically, orthographically, and with images, but primarily through typography, users make voice, gesture, and stance present in their tweets, digitally re-embodying the rich nonverbal expressivity of animation in talk. Finally, a study investigates notions of talk-like tweeting from an emic perspective, showing users' negotiations of how tweets can and should correspond to speech in relation to social identity, linguistic competence, and personal authenticity. Six chapters situate and synthesize the case studies in an expanded theoretical framework. Together, the studies show how Twitter's speech–writing hybridity extends beyond a mix of linguistic features, and challenges a traditional idea of writing as a mere representation of speech. Talk-like tweeting remediates (Bolter & Grusin, 2000) presence and embodiment, forgoing the abstraction of phonetic print literacy for nonverbal expressivity and an embodied written surface. Twitter talk is shown not simply to substitute literacy norms for oral norms, but to complicate and reconfigure these norms. Talk-like tweeting makes manifest an ongoing cultural renegotiation of the meanings of speech and writing in the era of digital social media.