English speakers learning Spanish should not confuse conocer with saber, another verb that can also be translated as "to know." The distinction between the two is covered in a separate lesson.
Generally, conocer means "to know" in the sense of to understand or to recognize a person, place or thing:
- ¿Conoces a tu enemigo? Do you know your enemy?
- No conocía la canción pero gracias a Google ya tengo la letra. I didn't know the song, but thanks to Google I now have the words.
- ¿Conoces tus derechos? Do you know your rights?
- Mi padre conoce México. My father knows Mexico.
- Sólo hace tres meses que nos conocimos. It has been only three months since we met.
- Conocí a tu sobrina. I met your niece.
Very close in meaning is reconocer, which is often translated as "to recognize." Conocer and reconocer are sometimes interchangeable; reconocer often suggests a more conscious or intentional form of knowing:
- ¿Cómo puedo reconocer que estoy recibiendo un tratamiento adecuado? How can I recognize that I am receiving a good treatment?
- La sociedad no quiere reconocer que hay drogadicción en la ciudad. Society doesn't want to admit that there is drug addiction in the city.
- Yo no reconocía su voz. I didn't recognize his voice.
More common is desconocer, which means "not to know": Desconozco su nombre pero no importa. I don't know his name, but that doesn't matter.
The noun form of conocer is conocimiento, which means "knowledge" or "body of knowledge" (such as a science):
- El acceso al conocimiento determina quién puede participar en la sociedad. Access to knowledge determines who can participate in society.
- Prueba tus conocimientos. Test your knowledge.
- No tengo conocimiento si ellos hayan sido invitados. I don't have knowledge if they have been invited.
- Pittsburgo es conocido como "la ciudad del acero." Pittsburgh is known as "the city of steel."
- La incidencia es mayor en mujeres que en varones por razones no conocidas. The incidence is greater in women than in men for unknown reasons.
- Cognición is roughly synonymous with conocimiento and is used as a scientific term.
- Incógnito means "unknown." As a masculine noun, el incógnito means an unknown reason. In mathematics, the feminine noun form, la incógnita, means an unknown quantity.

