In northern Mexico we say "seguido", it's not grammaticaly correct, but it's used in a day to day manner.

Voy seguido al cine => I often go to the movies Seguido me quedo tarde en el trabajo => I often stay late at work

"Frecuentemente" is more formal (and correct)

In northern Mexico we say "seguido", it's not grammaticaly correct, but it's used in a day to day manner.

• Voy seguido al cine => I often go to the movies
• Seguido me quedo tarde en el trabajo => I often stay late at work

"Frecuentemente" is more formal (and correct)