Bear in mind that some of these time expressions could be used with either the imperfect or the preterite tense, depending on context, but because these ones are rather vague you will often find them used with the imperfect tense.
- oftena menudo
- sometimesa veces
- every daycada dia
- each weekcada semana
- every monthcada mes
- every yearcada ano
- frequentlycon frecuencia
- from time to timede vez en cuando
- at that time (in history)en aquella época
- frequentlyfrecuente- mente
- usuallygeneral- mente
- many times, oftenmuchas veces
- a lotmucho
- nevernunca
- for a whilepor un rato
- alwayssiempre
- so many timestantas veces
- every weektodas las semanas
- every daytodos los días
- all the timetodo el tiempo
- several timesvarias veces