In linguistics, the term “island” generally refers to an extraction island, a syntactic domain that blocks extraction of a certain constituent out of it. For instance, a wh-phrase in English can be extracted across clause boundaries from its original position (marked by “t”, short for “trace”) in (1), whereas extraction is blocked out of a complex NP (an appositive clause or a relative clause) in (2). We therefore refer to the complex NP of (2) as a “complex NP island”. Similarly, extraction is impossible out of a subject island (a clau…