The SVO word order is used for both declarative and interrogative sentences (contrary to Spanish, subject/verb inversion does not exist in interrogatives). This holds for yes/no interrogatives as well as those introduced by question words that in Standard Spanish cause the obligatory switch from SVO to wh-VSO.
Source: Schwegler and Green 2007: 286
Source: de Friedemann and Patiño Rosselli 1983: 169