In the incessant attempts to overcome second language (L2) acquisition difficulties and to improve second language proficiency, most of the proposed methodological approaches which address this issue place high value on individual vocabulary and grammar of a second language and fall short of integrating lexical phrases/multi-unit expressions into the teaching approaches. This, if does not exacerbate acquisition difficulties, does not by any means improve it. On this view, the ubiquitous interest in lexical phrases gave rise to their investigation in language acquisition. This paper reviews the importance of lexical phrases in language acquisition by providing further insight into their peripheral role in first language and second language acquisition alike. Also, Evidence from neurolinguistic and psycholinguistic studies are provided to account for lexical phrases representation and brain-adaptability. Further, this paper suggests the implementation of lexical phrases, in general, and the Lexical Approach, in particular, in second language acquisition. Finally, further pedagogical implications as well as self-paced ones are proposed.

It is an ultimate goal for second language learners to attain a high-level of proficiency and produce L2 accurately as well as fluently. Yet, according to second language learning enormity particularly in a later stage, a considerable number of learners may experience excruciating difficulties. Suffice it to mention that some learners may not even succeed in developing language rudiments. To ascertain the learners' potential, second language acquisition theories have, for long, attempted to account for the difficulties faced by second language learners who tend to think and produce language in a rule-governed way. Inherent to such theories, explicit versus implicit learning approaches attempted to uncover the associated factors affecting second language learning. Accordingly, this has amassed a growing body of research over the issue of implicit learning which has been investigated in various disciplines including SLA and pedagogy, psycholinguistics, and cognitive and neuroscience. This paper places focus on implicit learning highlighting its importance in second language learning as well as its benefits which extend to language automaticity. The paper presents studies probing the effectiveness of implicit learning on various levels; after which neuroscientific data is presented to account for the advantages and development of implicit learning explicating the memory systems underpinning the learning process as well as the neural processes lying at the core therein. Finally, implications are provided.