1 Theoretical Perspectives on First Language Acquisition: a contrast between the nativists and interactionists perspectives 1 Abukari Kwame Department of Language and Culture The Arctic University of Norway, Tromso abukarikwames@yahoo.com June 2017 Abstract How children break into language has been a contested issue among both linguists and behavioural psychologists for a very long time. Among the various competing theories on child language acquisition are the universal grammar (nativism/innateness) and the interactionists perspectives. This paper explores how these two theories account for the acquisition of phonological and sign language by reviewing current research in the fields of child first language and simultaneous bilingual first language learners. And based on empirical research findings, I argue that at issue is the discourse on the role of input in language acquisition given that both theories agree on innate biological endowment to language learning. Hence, my conclusion is that, the innateness and interactionists arguments can be framed in terms of language competence and performance among first language learners. 1. Introduction Language acquisition has been a very fascinating phenomenon among humans, especially among infants. The acquisition of first language (L1A) is by far, the most interesting and debated issue among both linguistic researchers and behavioural psychologist, to which several theoretical proposals have been made. Starting from the second half of the 20th century, several questions were raised among researchers concerning the nature of language and how children acquire their L1. Among some of these questions were: How do children break into language? 1 An earlier draft of this paper was presented as course requirement in ENG-3040, First language Acquisition, and subsequently submitted as a Course paper in the same course. I am grateful to Prof. Yulia Rodina and the ENG-3040 Class for their comments and suggestions during the Course seminar.