Soler to express habits
In Spanish there is a verb which is specificly used to express habits both in the present and in the past. Soler is a modal verb that, as other modal verbs, are followed by an infinitive.
The English equivalents to these are I usually do and I used to do.
For example:
Yo suelo caminar los domingos por la mañana.
I usually walk on Sunday mornings.
Belén solía caminar los domingos por la mañana.
Belén used to walk on Sunday mornings.