What Is Easy and What Is Hard to Acquire in a Second Language?

In recent years, there has been increased interest in examining and explaining the differential difficulty of acquisition of language modules, interfaces, operations, and constructions (Lardiere 2005, 2008; Slabakova 2006, 2008; White, 2003). For example, a recent GASLA plenary, Lardiere 2005, argued that morphological competence should be accorded a special status and highlighted its difference from syntactic competence. This line of thought led Lardiere to propose the Feature Assembly Hypothesis. In a nutshell, the hypothesis postulates that learning a second language (L2) involves figuring out how to reconfigure the formal features of the native language and those available from UG into new or different configurations in the L2. It is precisely this assembly and re-assembly of formal features (which is almost never straightforward mapping) that is at the core of language acquisition. White (2003), chapter 4, asks the question of whether knowledge of inflectional morphology drives learning the syntax, or the other way around, knowledge of syntax comes before knowledge of inflectional morphology. She dubs the two views “morphology-before-syntax” and “syntax-before-morphology” (see more on this below). Slabakova (2006), building on White’s and Lardiere’s insights and viewing the issue from the point of modular critical periods in SLA, argues that there is no critical period for the acquisition of semantics; that is, meaning comes for free if the functional morpho-syntactic competence is already in place. It is critical that we use principled distinctions, well understood in linguistic theory, and solid bodies of data in defining this relative demarcation of linguistic processes and modules. The ultimate goal of this endeavor is, of course, to explain the cognitive process of language acquisition. However, this demarcation can also inform language teaching by applying the insights achieved by generative second language acquisition (SLA) research and theory in the last thirty years. It makes practical sense that if teachers know what is hard to acquire and practice it more in the classroom, learners will achieve better fluency and higher accuracy in the second language. In this paper, I will argue for the Bottleneck Hypothesis as a partial answer to the question of the title: what is easy and what is hard in second language acquisition. I will show that it is the functional morphology which is the bottleneck of L2 acquisition; acquisition of syntax and semantics (and maybe even pragmatics) flows smoothly (Slabakova, 2006, 2008). The hypothesis is based on a comparison of findings on the acquisition of inflectional morphology, syntax, the syntax-semantics interface, the syntax-discourse interface, and the semantics-pragmatics interface. I will summarize findings from representative studies in these areas to make the main point: inflectional morphology is the bottleneck of acquisition.