Habit time expressions
normalmente - usually
siempre - always
a veces - sometimes
nunca - never
cada día - every day
casi cada día - almost every day
cada martes - every Tuesday
Progress, Vol. 1
Progress, all volumes
Interleaving
Drilling one topic until it feels easy is tempting, but mixing different topics together builds more flexible, durable knowledge. The variety forces your brain to work harder, and that's what makes it last.