Resumen: The present chapter reviews theoretical and pedagogical insights in the field of ELT inspired by Vygotsky's (1986) research on the relationship between thinking and speaking and by consequent research into second language acquisition (SLA) from a sociocultural theory (SCT) perspective (Negueruela-Azarola, 2003; Lantolf and Thorne, 2006). From this, we examine the teaching of conceptual thinking in the ELT classroom, grounded in the idea that language learning is a transformative activity