This talk investigates LF/PF mismatches through the lens of wh-in-situ. Some wh-in-situ are truly in-situ at LF, and such wh-phrases are sensitive to so-called “intervention effects” (Hoji 1985; Beck 1996, 2006; Pesetsky 2000; among others). Such effects have been the topic of ongoing research since the 1980s, with multiple theories put forth about the nature of intervention and the correct characterization of the set of interveners. Based on novel data in Japanese and English, I show that there is no fixed set of interveners. Instead, I propose that intervention reflects a particular, universally uninterpretable configuration at LF. Languages vary in the strategies available to them to avoid this LF configuration.
There are also wh-in-situ which do move at LF. Considering island effects, a famous diagnostic of movement, I show that covert wh-movement takes place in some English interrogative LFs, but that it at the very least *can*, and sometimes *must*, be a short movement step targeting a position other than that targeted by overt wh-movement. As a consequence, I argue that covert wh-movement is a restricted, local operation, similar to scrambling in languages like German and Japanese.
This investigation of LF syntax in English and Japanese will lead to a variety of implications for grammar, including for the A-bar probing system, the nature of overt vs covert movement, the scope-taking operations available to the grammar, successive-cyclicity and reconstruction, and language acquisition and cross-linguistic variation.