In order to be able to account for the alternating and non-alternating uses of mood in Spanish this paper explores the Held of illocution and modality and argues for two elaborations of the Functional Grammar framework: (i) a representation of main clauses which distinguishes between several layers, each representing a different subact of the speech act, and (ii) a representation of noun clauses which distinguishes between non-factive, factive, and semi-factive complements.