 As secretary of the National Language Committee of the Philippine Constitutional Convention (1971–1973) during the presidency of Ferdinand E. Marcos, he favored Tagalog to become the basis of the country's national language.In the same convention, he joined forces with other nationalists to preserve Spanish as one of the country's official languages.Spanish, however, was later made an optional language (together with Arabic) under the Constitution of 1987 which was promulgated under the presidency of Corazón Aquino who abolished the 1973 constitution under Marcos.