Saber vs Conocer

English has one verb, "to know", doing two very different jobs: knowing a fact and knowing a person. Spanish refuses to merge them. Saber is for facts, information and skills. Conocer is for acquaintance and familiarity. They almost never overlap, which makes this an easier split than ser vs estar once the principle lands.

• Sé dónde vive. (I know where he lives.) - information, saber
• Conozco su casa. (I know his house.) - familiarity, conocer

Saber: facts, information, know-how

Saber is knowledge you can state, recall or perform. Three jobs:

Facts and information, usually followed by que or a question word:

• Sé que mañana es lunes. (I know that tomorrow is Monday.)
• No sé dónde está. (I don't know where it is.)
• ¿Sabes a qué hora llega? (Do you know what time he arrives?)

Knowing a piece of data - a fact treated as an object:

• ¿Sabes su nombre? (Do you know his name?)
• No sé la respuesta. (I don't know the answer.)

Know how to, with saber plus an infinitive. This is the one English handles with two words:

• Sé nadar. (I know how to swim / I can swim.)
• Mi madre sabe cocinar muy bien. (My mother knows how to cook very well.)

Note there is no extra word for "how": saber plus infinitive carries it. Saying sé cómo nadar is a calque from English and sounds wrong.

Conocer: people, places, things

Conocer is acquaintance - being familiar with someone or something through experience. It takes a direct object, never que and never an infinitive.

People (with the personal a):

• Conozco a tu hermano. (I know your brother.)
• ¿Conoces a alguien aquí? (Do you know anyone here?)

Places:

• Conozco bien Madrid. (I know Madrid well.)
• No conozco esta zona. (I don't know this area.)

Things and subjects - in the sense of being acquainted with, familiar with, having experience of:

• Conozco esa canción. (I know that song.)
• Conoce muy bien su trabajo. (He knows his job very well.)

That last pair is worth dwelling on. Sabe su trabajo would mean he knows the facts of it cold; conoce su trabajo means he is experienced and at home in it. English blurs the two; Spanish does not.

The conjugations and the irregular yo

Both are regular -er verbs in the present except for the first person singular.

Sé carries a written accent to keep it apart from the reflexive pronoun se. Conozco inserts a -zc- before the o - the same pattern you will meet in parecer (parezco), ofrecer (ofrezco) and many other -cer verbs.

The preterite trap

In the preterite, both verbs shift meaning to the moment the knowing began.

• conocí = I met (for the first time), not "I knew"
  • Conocí a Pedro el año pasado. (I met Pedro last year.)
• supe = I found out, I learned, not "I knew"
  • Supe la verdad ayer. (I found out the truth yesterday.)

For the ongoing past state, use the imperfect:

• conocía = I knew / was acquainted with
• sabía = I knew (a fact)
  • Ya conocía a Pedro; sabía que era de Madrid. (I already knew Pedro; I knew he was from Madrid.)

This is the single most common stumble for intermediate learners. Conocí a María is a first meeting, not a description of an old friendship.

Worked contrasts

• Sé su número (I know his number - the data) vs conozco a su hermano (I know his brother - the person).
• ¿Sabes Madrid? is wrong; you can know facts about Madrid with saber que..., but you are acquainted with the city with conozco Madrid.
• Sabe tocar la guitarra (he knows how to play the guitar - skill) vs conoce esa guitarra (he knows that particular guitar - familiarity).

Common mistakes English speakers make

Using conocer for facts. "I know that it's late" is sé que es tarde, never conozco que es tarde. Facts and que clauses are always saber.

Using saber for people. "I know María" is conozco a María, never sé a María. People are conocer territory, and they take the personal a.

Adding cómo after saber. "I know how to drive" is sé conducir, not sé cómo conducir. The infinitive alone carries the "how to".

Reading conocí as "I knew". In the preterite it means I met. For the lasting state, reach for the imperfect conocía.

See also

• The ser vs estar page covers the other famous one-English-word, two-Spanish-verbs split.
• The personal a page explains the little a that conocer needs before a person.
• The Spanish verbs page has the full conjugation of saber and conocer across every tense.