Children have an enviable capacity for acquiring competence in whatever language or languages they get exposed to and in a manner so rapid, so creative, so uniform, so systematic, so regular and indeed so easy compared with the mammoth task that they within a remarkably short span of time accomplish victoriously. This marvellous phenomenon unique only to humans has instigated scholars to propound various theories that aim to account for this feat, where some have argued that language is a genetic capacity originating from the brain, while others contended to look at it as a system originating from the environment. While the former approach views language acquisition as “genetically endowed and readymade,” the latter sees it as “environmentally fashioned and evolving”. Using the descriptive method, this paper, following a brief discussion of early bilingualism, and an initiatory section on “the father of modern linguistics,” explored and contrasted, within this context, these approaches concerning the processes and source of linguistic knowledge. Emphasising a third view, the sociolinguistic approach, the paper verified that language acquisition and learning was neither solely the result of innate knowledge (first position); nor the progeny of the environment of the child alone (second position); but rather the product of and interplay between both social interaction and cognitive development. Key words: Language acquisition, genetic capacity, process, innate knowledge, environment, social interaction, behaviourists, mentalists, environmentalists, sociolinguistic, social semiotic.