[1][2] He was a disciple of Francisco Rodrigues Adrados, though later in his career he developed independent views and ideas.
[3] Francisco Villar Liebana has completed several studies on the Paleohispanic languages, particularly on Celtiberian phonetics and morphology, contributing to the understanding and appreciation of the Botorrita Bronzes (one of the most relevant testimonies of celtiberian writings), and more generally on Continental Celtic and to the development of studies about the Tartessian and Lusitanian languages.
[4] He has also contributed to the development of the Indoeuropean Linguistics, supporting the Kurgan hypothesis proposed by Marita Gimbutas,[5] and opposing to the Neolithic hypothesis proposed on the basis of archeology, by Colin Renfrew.
Lenguaje e historia (1991), translated into several languages and considered a reference text book for current Indoeuropean studies.
During 1977-78, he translated Kalidasa's Meghdoot and The Brihadaranyak (Upanisad del Gran Aranyak) to Spanish.