This paper proposes a distinction between two classes of verbs of emission, emission of substance, such as sangrar, 'to bleed', and manner of emission, such as crujir, 'to creek'. Both of them can produce Eventive Infinitives (Demonte and Varela 1997), although only one of these classes, verbs of manner of emission, can produce Perception Eventive Infinitives (PEI), which are selected by perception verbs (Oí el arrastrar de los muebles por la puerta, lit. 'I heard the drag.INF of the furniture through the door'). We propose adopting a configurational analysis that focuses on the abstract representation of the word on a (lexical-)syntactic level (Hale and Keyser 1993, 2002, Marantz 1997, 2001), instead of the lexicalist explanation, based on the idiosyncratic properties of each specific lexical item. Emission of substance verbs cannot produce PEIs because in their underlying structure they contain an internal argument that measures the event, while PEIs denote necessarily unbounded events. The internal argument is not present in manner of emission verbs, which contain instead an abstract preposition of manner, a configuration that licenses PEIs.