Both can translate as 'conocer', but one is the first encounter and the other is ongoing familiarity.
Verb. To encounter someone for the first time. It is the moment of the first meeting.
I met my best friend in college.
Conocí a mi mejor amigo en la universidad.
Nice to meet you!
¡Mucho gusto! / ¡Encantado de conocerte!
Where did you two meet?
¿Dónde se conocieron ustedes dos?
Verb. To be acquainted with someone. Ongoing familiarity with a person.
Do you know her? She is my sister.
¿La conoces? Es mi hermana.
I have known him for over ten years.
Lo conozco desde hace más de diez años.
She knows everyone in this neighborhood.
Ella conoce a todos en este vecindario.
Common mistake
Saying "I knew him yesterday" when you mean you encountered him for the first time. (correct: I met him yesterday.) "Knew" implies a pre-existing relationship.
Trick to remember it
"Meet" = first contact, the moment you are introduced or cross paths with someone for the first time. "Know" = ongoing relationship, they are already in your life. First time? "I met him." Already in your life? "I know him."
Quick rule
Is it the first encounter with that person? Use "meet". Is there already a relationship or familiarity? Use "know".
Did you know?
In Spanish, "conocer" in the preterite (conocí) implies first encounter, like "met". In the present (conozco) it implies familiarity, like "know". English simply uses two separate words for the two cases, without depending on verb tense to make the distinction.
Exercise 1 · Pick the right one
I _____ my husband at a work conference in 2018.
Exercise 2 · Pick the right one
Do you _____ him? He is my neighbor.
Exercise 3 · Form the word
Is it the first encounter with that person? Use "meet". Is there already a relationship or familiarity? Use "know".
Saying "I knew him yesterday" when you mean you encountered him for the first time. (correct: I met him yesterday.) "Knew" implies a pre-existing relationship.
"Meet" = first contact, the moment you are introduced or cross paths with someone for the first time. "Know" = ongoing relationship, they are already in your life. First time? "I met him." Already in your life? "I know him."
Bryan López
Founder of SpeakUP Academy