In Spanish verbs associated with three participants – Agent, Theme and Recipient – may appear in alternating constructions, where the 3rd person recipient argument is realized as a prepositional phrase (PP) (Pedro envió una carta a María ‘Peter sent a letter to Mary’) or as one doubled by a clitic (Pedro le envió una carta a María ‘Pedro sent Mary a letter’), the latter being referred to as an indirect object (IO). This paper provides a corpus-based study of the distributional patterns of the two constructions that includes both give-type and send-type verbs. The analysis of PPs and IOs in terms of referential properties shows that both have a strong tendency to be [+definite]. However, the distribution of the IO is more constrained than the PPs in terms of certain referential properties, although there are some lexical differences observed among the verbs. The PP, on the other hand, is free of any restrictions. One important contribution of this study is that it provides empirical evidence that the IO associated with the role of Recipient behaves very differently from the one assuming other roles: clitic doubling, which has become the norm for the latter, is still very restricted for the former, contrary to what has been commonly assumed.