The aim of this Ph. D dissertation is to analyze, through qualitative methodologies, textbooks for learning Chinese as a Foreign Language (ChFL) for Spanish speakers. Special attention has been paid to one of the most complex areas in ChFL: the particle 了/le/, in order to gain deeper insight into some of the aspects of curriculum design and pedagogic planning in the textbooks for teaching ChFL. Our instrument of analysis was developed by drawing from two sources. Firstly, from a solid theoretical foundation which took into account 7 different disciplines of Language Science: 1) the Cognitive Linguistics, 2) the Pedagogic Grammar, 3) theories about second language acquisition (SLA), 4) Second and Foreign Language teaching approaches, 5) studies on the development and analysis of curriculum and study materials 6) Spanish-Chinese Tense and Aspect system studies and comparison, and 7) studies of the particle了, not only from the linguistic and pragmatic-communicative perspective, but also from discursive, sociocultural and cognitive perspectives. Secondly, the opinions of 10 experienced ChFL teachers and students were considered to enable the analysis to incorporate both theoretical and practical perspectives. Finally, a 4 levels analysis instrument with 6 parameters and 24 variables, each of them covering one specific pedagogic or linguistic perspective was designed for analyzing three series of textbooks (three levels each, 9 volumes in total), namely: 1) El Nuevo Libro de Chino Práctico I, II y III, 2) El Chino de Hoy I, II y III y 3) Hanyu-Chino para hispanohablantes I, II y III. The particle 了 has also been used as a filter for selecting our target lessons, as opposed to selecting lessons at random. After analyzing the data with the designed instrument a conclusion has been made, which we hope will contribute to the further development and improvement of ChFL teaching and learning.