In Spanish, there are two verbs that express the idea "to know." These two verbs are "saber" and "conocer." The verb you choose depends upon the context in which it is used.
The same sort of situation exists with respect to the two Spanish verbs pedir and preguntar. They both mean "to ask" but they are not interchangeable.
http://www.studyspanish.com/lessons/sabcon.htm
THE USE OF SABER OR CONOCERWrite S for Saber or C for Conocer to indicate the proper translation of “know.”
___ 1. I know her. ___ 2. You know where her house is located. ___ 3. We know how to write. ___ 4. He knows the principal’s name. ___ 5. They don’t know the teacher. ___ 6. All of you know Spanish.