Typologically, many languages have indefinite pronouns that are derivedfrom interrogative pronouns. In fact, some indefinite pronouns assume the same morphological shape as their interrogative counterparts. Such words are termed quexistentials: they take on an indefinite or interrogative reading depending on the sentence environments in which they are licensed. Hengeveld et al. (2021) argue that indefinite quexistentials only appear in non-focused environments, whereas their interrogative counterparts only appear in focused environments. With San- tiago Laxopa Zapotec (Oto-Manguean) as the empirical focus of this thesis, I expand the typology of quexistentials presented by Hengeveld et al. (2021) and argue that indefinite and interrogative quexistentials are not always in comple- mentary distribution, providing elicited data from native speakers of Santiago Laxopa Zapotec as evidence. I use Karttunen’s (1977) semantics for questions to unite indefinite and interrogative quexistentials into having the same general- ized quantifier semantics. The difference in their interpretations arises from the syntax-semantics interface – in particular, whether the quexistential composes with an interrogative operator.