Intervention and focus in Asante Twi

This paper concerns the distribution of wh-words in Asante Twi, which has both a focus fronting strategy and an in-situ strategy. We show that the focusing and the in-situ constructions are not simply equally available options. On the contrary, there are several cases where the focusing strategy must be used and the in-situ strategy is ungrammatical. We show that the cases in Asante Twi are "intervention effects", which are attested in other languages, like German, Korean, and French. We identify a core set of intervening elements that all of these languages have and discuss their properties.