AbstractThis paper analyses the combinatorial restrictions that operate in clitic clusters in certain Eastern Iberian varieties (Aragonese, Spanish, and Catalan). In particular, I focus on the combination of third person clitics. As it is well known, in some Romance varieties the combination of a third person accusative clitic and a third person dative clitic is banned (the so-called ∗le lo restriction, Bonet, Eulàlia. 1991. Morphology after syntax: Pronominal clitics in Romance. Cambridge: Massachusetts Institute of Technology Dissertation; Cuervo, María Cristina. 2013. Spanish clitic clusters: Three of a perfect pair. Borealis: An International Journal of Hispanic Linguistics 2. 191–220; Nevins, Andrew. 2007. The representation of third person and its consequences for person-case effects. Natural Language & Linguistic Theory 25(2). 273–313; Ordóñez, Francisco. 2002. Some clitic combinations in the syntax of Romance. Catalan Journal of Linguistics 1. 201–224, Ordóñez, Francisco. 2012. Clitics in Spanish. In José I. Hualde, Antxon Olarrea & Erin O’Rouke (eds.), The handbook of Spanish Linguistics, 423–453. Malden: Wiley-Blackwell; Perlmutter, David. 1971. Deep and surface structure constraints in syntax. New York: Holt, Rinehart & Winston). In order to license this troublesome combination, languages resort to different ‘repair strategies’ modifying the structure of one of the merged clitics. In the literature on clitic combinations, there have been two main proposals of analysis: morphological and syntactical. In this paper, I put forward an analysis based on the Distinctness Condition (Hiraiwa, Ken. 2010. The syntactic OCP. In Yukio Otsu (ed.), The proceedings of the 11th Tokyo Conference on Psycholinguistics, 35–56. Hituzi: Tokyo; Neeleman, Ad & Hans van de Koot. 2005. Syntactic haplology. In Martin Everaert & Henk van Riemsdijk (eds.), The Blackwell companion to syntax, 685–710. Wiley-Blackwell; Perlmutter, David. 1971. Deep and surface structure constraints in syntax. New York: Holt, Rinehart & Winston; Richards, Norvin. 2010. Uttering trees, vol. 56. Cambridge, MA: MIT Press; Van Riemsdijk, Henk. 1998. Categorial feature magnetism: The endocentricity and distribution of projections. The Journal of Comparative Germanic Linguistics 2(1). 1–48; Yip, Moira. 1998. Identity avoxidance in phonology and morphology. In Steven G. Lapointe, Diane K. Brentari & Patrick M. Farell (eds.), Mophology and its relation to phonology and syntax, 216–246. Stanford, CA: CSLI). Specifically, I argue that the restrictions that constraint clitic combinations are due to the impossibility to linearize two identical syntactic objects, such as <XP, XP> (Chomsky, Noam. 2013. Problems of projection. Lingua 130. 33–49; Chomsky, Noam. 2015. Problems of projection. In Elisa Di Domenico, Cornelia Hamann & Simona Matteini (eds.), Structures, strategies and beyond: Studies in honour of Adriana Belletti, 1–16. Amsterdam: John Benjamins; Moro, Andrea. 2000. Dynamic antisymmetry (No. 38). Cambridge, MA: MIT Press; Richards, Norvin. 2010. Uttering trees, vol. 56. Cambridge, MA: MIT Press). From this perspective, cross-linguistic variation is the result of different ‘repair strategies’ languages deploy to make <XP, XP> objects linearizable (Richards, Norvin. 2010. Uttering trees, vol. 56. Cambridge, MA: MIT Press).