The goal of this squib is to provide several empirical arguments that support the view that the real verbal predicate in Spanish are the theme vowels that appear combined with what is traditional regarded as the lexical verb. In a nutshell, theme vowels are light verbs - in fact, I argue for total structural identity between theme vowels, verbalisers and light verbs in the sense that they identify the same position within the verbal structure. If these arguments are right, we would be one step closer to reducing what seems to be surface, idiosyncratic morphological variation to well-defined syntactic or semantic properties of universal structures.