The "trans-" turn in language studies illuminates human communication as the coordination and interpretation of a vast array of semiotic resources that are entangled with language in fluid and unpredictable ways. It also highlights the current era of globalization in which communication occurs with ever-increasing rapidity among ever-expanding audiences, through rapidly changing semiotic means and modes. It transcends the local, to become translocal and transnational, indexing the diversity of actors engaged in new configurations of communicative engagements. Framed by notions of repertoires and modalities, in this article I offer a rationale for and close articulation of transmodalities, to more fully consider processes of semiosis across place, space, and time. Because meanings matter--especially relational aspects of communication--I propose critical cosmopolitanism to account for humane, ethical approaches to human engagements and their outcomes. I provide data from a project that connects youth across the globe through technology-mediated communications to demonstrate how these dual frames--transmodalities and critical cosmopolitanism--can serve as guideposts and heuristic lenses for transnational interactions, relations, and learning in a globalized, technologized world.