The Interface Hypothesis proposes that second language (L2) learners, even at highly proficient levels, often fail to integrate information at the external interfaces where grammar interacts with other cognitive systems. While much early L2 work has focused on the syntax-discourse interface or scalar implicatures at the semantics-pragmatics…

Recently, there has been considerable L2 research on interfaces between different modules of grammar (internal), such as syntax-semantics, or between grammar and other cognitive systems (external), such as semantics-pragmatics. Sorace's (2011) Interface Hypothesis proposes that L2 learners, even at highly proficient levels, often fail to integrate…