As linguistic diversity is raising in schools worldwide, inquiry is needed to explore how to modify teaching and learning contexts in response to emerging multilingual students’ different needs. Grounded in sociocultural theory, this inquiry explored how teachers employed discourse differently to respond to diverse students’ needs as they participated in a language programme that brought together multicompetent language users, Spanish-expert students learning English, and English-expert students learning Spanish in secondary school. Exploring transcripts of student and teacher interactions, the paper distinguished discursive patterns that teachers used to mediate multilingual language-learning opportunities, to raise language awareness, and to cultivate a collective zone of proximal development in a linguistically diverse context. Findings elucidate the ways that teachers employ languaging and translanguaging as mediational tools to gauge and respond to students’ needs, while drawing upon students’ funds of knowledge to deepen multilingual and multidirectional language-learning opportunities. The findings have implications for how educators can differentiate their discourse/instruction to support students’ multilingualism and ultimately increase language-learning opportunities amid linguistically diverse students.