From Day 3: Abajo (Downstairs)
¿Cómo sabes mi nombre?
In a question, cómo (“how”) carries a written accent.
Hear it in the conversation
Marta
Sí… ¿Cómo sabes mi nombre?
Yes… How do you know my name?
Without it, como has other jobs: on day 2 you saw como tu abuela (“like your grandmother”), and yo como means “I eat.” They sound the same; the accent marks the question word in writing.