I'd like to get some clarification on the uses of costumarse. I would assume it means used to like getting accustomed to. That would make sense etymologically. THough, is it also used to represent the past tense like Duo suggests? I thought I could just make the following verb in the passado imperfeito for that. Thanks!!
Present habitual: costumo (present) acordar cedo / eu estou acostumado a acordar cedo. (Im used to waking up early). Eu costumava (pretérito imperfeito) acordar cedo para ir à escola / eu acordava (pretérito imperfeito) cedo para ir à escola (i used to wake up early to go to school). Eu acordei cedo para ir à escola (i woke up early to go to school). Pretérito imperfeito is also used to express regular things that happened in the past, no need to use "costumar". But you can also use "costumar" in pretérito too, no problem