Saber and conocer both translate to “to know,” but Spanish splits knowing into two different things — and they’re not interchangeable. Once you see the split, the choice is usually instant.
Saber is knowledge in your head — facts, information, and skills you could state or perform. Conocer is firsthand familiarity — people you’ve met, places you’ve been, things you’ve experienced.
A quick test: could you write the knowledge down? Then it’s saber. Did you have to be there / meet them to have it? Then it’s conocer.
1. When to use SABER
Saber is used for facts and information — very often introduced by a question word (qué, dónde, cuándo, por qué, cómo) or que/lo que — and skills with saber + infinitive (“to know how to”):
If what follows is a clause (…que, …dónde, …cuándo, …por qué) or an infinitive, you're looking for saber, not conocer.
2. When to use CONOCER
Conocer is used for familiarity with people, places, and things — typically followed by a noun or noun phrase. With people, it brings the personal a:
Knowing a person always uses conocer a, never saber. And watch the preterite: with people, conocí often means “I met”, while supe often means “I found out.”
3. The side-by-side test
Same sentence topic, different kind of knowing:
Saber = stateable
Facts, answers, and how-tos you could put into words.
Conocer = connected
People, places, and things you know through firsthand familiarity.
If you could Google the answer, think saber. If you had to experience it firsthand, think conocer.