The article compares the conditions of clitic climbing in modern and medieval Spanish. The purpose of this comparison is to prove and illustrate - using the examples of a medieval text in prose - that conditions of clitic climbing vary during the different stages of the evolution of Spanish.
Spanish and Portuguese, the two most representative Iberoromance languages, coincide in having preserved the phenomenon of clitic promotion since ancient times. According to certain theories, the realization or non-realization of the promotion depend on the structural characteristics of the constructions made up of a regent verb and a dependent infinitive. The detailed analysis of the phenomenon mentioned above in a medieval and a modern corpus presented in this article demonstrates that, in spite of the apparent similarities, there are considerable differences between the structure of the constructions composed of a regent verb and an infinitive in the two periods.