8) which they master as they grow, using it as their most effective means of interacting and identifying them in many ways. For example, through language people’s nationality, profession, education, and even values can be sensed. Hence, “when we study human language, we are approaching what some might call the ‘human essence’, the distinctive qualities of mind that are, so far as we know, unique to [humans]” (Chomsky, cited in Fromkin & Rodman, 1998: 3). With language being distinct to humans, it is believed that, languages best mirror the human mind (Leibnitz, cited in Chomsky, 1986, p. 1).
Thus, language study is important and fascinating, specifically the study of language acquisition. As Bloomfield (1933) said: “the acquisition of language is doubtless the greatest intellectual feat anyone of us is ever required to perform” (p. 29). If children’s effortless acquisition of first language (L1) raises many questions, the impact of L1 acquisition on second language (L2) acquisition raises more questions, especially in considering its implications on L2 teaching.
LA, a field of study that has earned much attention and controversy, is used interchangeably with language learning (LL). For instance, Quine (1960) defines LA as just another term for LL, as the mental capacities used in acquiring a language are the same mental capacities used in learning a wide array of other skills. But Chomsky (1969) and Krashen (1981), in different contexts, define LA and LL as two different processes. For Chomsky, children acquire and master their L1 as they develop, yet they learn their L1 differently compared with their learning other things, like using cutlery (cited in Chapman, 2000, p. 159). While, Krashen (1981) differentiates LA and LL in the context of second language acquisition (SLA), wherein LA is the process by which children acquire their L1 and L2,