What is the English translation of the Spanish words que paso?

¿que pasó? (with the accent) means "what happened?" (from the preterite tense). although i think you probably mean "que pasa" (ending in an "a"). This means "what is happening?" (present tense) and you will hear it a lot. its like the English "what´s up"

hola, ¿que pasa? = hi, whats up/whats happening? Hola que paso is mostly used in California as a greeting for younger people.