saber

"To know" a fact, or "to know how to" do something (always + infinitive, no preposition: sé nadar). This is the half of Spanish's most notorious verb-pair confusion for English speakers — see conocer for the other half, directly parallel to French savoir/connaître.

• Sé hablar japonés. — I know how to speak Japanese.
• ¿Sabes dónde vive? — Do you know where she lives?
• No sé la respuesta. — I don't know the answer.

English only has one verb, "to know," for both facts/skills (saber) and people/places (conocer) — so learners default to saber everywhere. "I know Mexico City" is conozco Ciudad de México, never *sé Ciudad de México.*

Often confused with conocer.

• quote "El saber es poder" — The common Spanish rendering of Francis Bacon's Latin aphorism "scientia potentia est" ("knowledge itself is power") — the phrase's first recorded use is actually in Thomas Hobbes's 1668 Latin edition of Leviathan, though it's popularly attributed to Bacon, whom Hobbes served as a young secretary.
• expression "El saber no ocupa lugar" — A widely used Spanish proverb, listed in the Instituto Cervantes's Refranero Multilingüe, meaning that learning something new is never a disadvantage — literally "knowledge doesn't take up space," used to encourage curiosity.