The paper argues that language teaching and learning/acquisition are both activities that involve interaction between the teacher and the learner. However, to create knowledge, the teacher is required to facilitate and guide learners to discover. In constructivism theory of learning, while learning is not only individual but active, knowledge creation is socially constructed.Thus, language learner must be enabled to independently learn and socially interact with others to acquire linguistic knowledge that a learner will eventually use to interact with others in the real world. These practices are informed by constructivism as it deals with the nature of knowledge and the way knowledge is created.This article presents the term constructivism as both theory of learning and philosophical concept. In this regard, principles and assumptions of the theory of constructivism as propounded by its proponents, viz.: Immanuel Kant, Jean Piaget and Lev Vygotsky have been revisited to establish its link with language teaching and second language acquisition. To bring implication onto light, this article selected five key theoretical [case] studies underpinning the connection between constructivism and language teaching and second language acquisition. As a result, it is found that language teaching and learning/acquisition are both activities that involve interaction between the teacher and the learner. However, to create knowledge, the teacher is required to facilitate and guide learners to discover. In constructivism theory of learning, while learning is not only individual but active, knowledge creation is socially constructed. In this way, language learner must be enabled to independently learn and socially interact with others to acquire linguistic knowledge that a learner will eventually use to interact with others in the real world. These practices are informed by constructivism as it deals with the nature of knowledge and the way knowledge is created. The article, therefore, concludes that in language teaching and learning, both nature and nurture should be supported by creating an enabling environment in which linguistic knowledge is constructed.TRANSLED Project