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

casi nunca

for one single time

una vez

for a single instance

una vez

for two instances

dos veces

on a very infrequent basis

raramente

used to refer to something that happens rarely or infrequently

raramente

on very rare occasions

infrecuentemente

in an infrequent and unpredictable manner

esporádicamente

not on regular occasions

inusualmente

not on a regular basis

ocasionalmente

on irregular but not rare occasions

on occasions that are not regular or frequent

at moments that are not constant or regular

a veces

at infrequent intervals

ocasionalmente

at irregular intervals

periódicamente