Since Selinker (1972) coined the term fossilization to characterize the phenomenon in which second language (L2) learners cease to progress in the acquisition process, much effort (e.g., Bates & MacWhinney, 1981; Krashen, 1981, cited in Han & Odlin, 2006) has been made to research instances of such premature stabilization of deviant L2 forms both within and across learners. Nonetheless, as Birdsong (2003, cited in Han & Odlin, 2006) aptly points out, the term has been (mis)used by many simply as a “catch-all” term, i.e., a handy metaphor for describing any lack of progress in L2 learning, regardless of its nature. It is therefore not surprising that little has been achieved as far as the development of a comprehensive analytic model throughout almost forty years of fossilization research. Against this background, Han (2009) proposes the Selective Fossilization Hypothesis (SFH), seeking to account for the fossilizability of target L2 structures through establishing: (1) empirically operationalizable variables (i.e., first language (L1) markedness and L2 input robustness) and subvariables (i.e., frequency and variability); (2) a first-of-its-kind analytiical model of fossilization, whose “boundary conditions” still require further investigation.