Spanish nationality isn’t gated by language alone. You need DELE A2 Spanish and a separate civics exam, and the residency clock itself varies dramatically by where you’re from.
Standard residency before applying for nationality: 10 years, continuous, legal, immediately before the application. But Spain shortens this dramatically for specific groups — 2 years for nationals of Ibero-American countries, Andorra, the Philippines, Equatorial Guinea, Portugal, or people of Sephardic origin; 1 year for those born in Spain or married at least a year to a Spanish national; 5 years for refugees. Time spent on a student visa doesn’t count toward any of these clocks.
DELE A2 (or higher) Spanish, administered by Instituto Cervantes — the certificate doesn’t expire. Exempt if you’re a national of a Spanish-speaking country.
CCSE (Conocimientos Constitucionales y Socioculturales de España) — 25 questions on Spanish constitutional structure, government, history and culture. Required of every applicant 18 or older, regardless of nationality, also via Instituto Cervantes, held monthly except August and December.