Adverbios de Tiempo y Lugar - Adverbios de baja frecuencia

not at any point in time

nunca

on any occasion

alguna vez

in a manner that almost does not occur or happen

for one single time

una vez

for a single instance

for two instances

dos veces

on a very infrequent basis

raramente

used to refer to something that happens rarely or infrequently

rara vez

on very rare occasions

in an infrequent and unpredictable manner

not on regular occasions

not on a regular basis

ocasionalmente

on irregular but not rare occasions

de vez en cuando

on occasions that are not regular or frequent

de vez en cuando

at moments that are not constant or regular

a veces

at infrequent intervals

at irregular intervals