Sunday is "domingo," which is pronounced as it is written.
Monday, is "lunes" which is pronounced as LOO-nays.
The third day of the week, Tuesday, is "martes" or MAR-tays.
The fourth day of the week, Wednesday, is "miercoles" which is pronounced me-AIR-ko-lays.
The fifth day of the week, Thursday, is "jueves," which is pronounced WAY-beys. The "j" is pronounced as an "h" and the "v" sounds a lot like a "b."
The sixth day of the week, Friday, is "viernes" which is pronounced bee-AIR-nays.
The seventh day of the week, Saturday, is "sábado," which is also the word for sabbath. There is an accent on the first syllable. Say SA-ba-doh.