It's a common phrase used to teach about the days of the week.
The missing word is "Tuesday" (martes in Spanish).
So the full phrase would be: "Si hoy es lunes mañana será martes."
It's a common phrase used to teach about the days of the week.
The missing word is "Tuesday" (martes in Spanish).
So the full phrase would be: "Si hoy es lunes mañana será martes."