From the introduction: "In this paper I survey various constructions in Spanish that involve indirect objects. I claim that many final 3's in Spanish do not head initial 3-arcs, in particular, those that appear in Causative Clause Union, in the Inalienable Possessor construction, in Inversion, and in constructions in which the final 3 is an initial Oblique.
"The analysis and discussion is carried on within the framework of Relational Grammar (Perlmutter, 1980, and to appear, a and b). I present an argument that because Relational Grammar posits initial syntactic relations that are distinct from both semantics and final syntactic relations, it is capable of capturing generalizations about Spanish structure (especially the phenomenon of clitic doubling) that are difficult to capture in frameworks that do not include this theoretical proposal.
"The paper is organized as follows: In section 1, I present analyses (most of which have appeared previously in the literature) of various types of final 3's in Spanish. Section 2 discusses characteristics that all final 3's share, justifying their inclusion together in one syntactic class. Section 3 demonstrates that this class is not completely uniform, and that class-internal differences may be characterized in terms of the analyses in section 1. In particular, I argue that the phenomenon of clitic doubling provides evidence that most types of final 3's are not initial 3's. This section thus provides new arguments for these analyses, in addition to those that have appeared previously. Section 4 briefly discusses some alternative proposals that are precluded by the facts presented in this paper, and summarizes the arguments from Spanish indirect objects for claiming that it is necessary to distinguish the three notions: semantic role, initial syntactic relation, and final syntactic relation."
Bickford, J. Albert
"Initial and non-initial indirect objects in Spanish,"
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 26, Article 1.
Available at: https://commons.und.edu/sil-work-papers/vol26/iss1/1