Наречия Времени и Места - Наречия низкой частоты

not at any point in time

никогда

on any occasion

всегда

in a manner that almost does not occur or happen

вряд ли когда-нибудь

for one single time

один раз

for a single instance

один раз

for two instances

два раза

on a very infrequent basis

редко

on a very uncommon basis

редко

on very rare occasions

не часто

in an infrequent and unpredictable manner

спорадически

not on regular occasions

необычно

not on a regular basis

время от времени

on irregular but not rare occasions

порой

on occasions that are not regular or frequent

время от времени

at moments that are not constant or regular

время от времени

at infrequent intervals

иногда

at irregular intervals

периодически