The English article system is extremely complex because of its conceptual abstractness and context-dependent usage. For these specific features, some second language learners (e.g., Japanese) find article acquisition to be very difficult. Traditionally, the definite article the is thought to express exclusively the referential function of "identifiability", that is, the is there to identify or pick out the referent so the hearer can identify what is being discussed (Lyons, 1999). This view has been widely accepted and has served as the foundation of research as well as for pedagogical orientations. Recently, however, these traditional notions have been heavily criticized as 'insufficient'. As a result, a cognitive, mental space notion of "accessibility" has been introduced (Epstein, 2002).