Revised text of a talk given at the 9th International Conference on Greek Linguistics 29 October 2009 - 31 October 2009 Chicago, Illinois In this paper I address the issue as to why there are at first glance three items that can introduce an embedded question in Classical Greek: hós (relative), tís ((direct) interrogative) and hóstis (so-called indefinite relative). Though, a closer examination shows that this threefold possibility is limited to the set of responsive question-embedding predicates. Moreover, tís patterns with hóstis in that both can also be used after rogative predicates. Therefore the distinction is amenable to a binary one. Giannakidou's 1998 notion of non-veridicality accounts for it: tís and hóstis prove to be licensed by non veridical contexts. Hós clauses are nothing else than actual Free Relative clauses, that function as concealed questions, or, better said, as concealed propositions. To explain this, I resort to Jacobson's (1995) theory of Free Relatives and to a type-shifting operation, already called for in Nathan (2005).