| now and then(expression, idiom, adverb, time, moment) |
| occasionally(expression, adverb, time, moment, continue) |
| once in a while(expression, adverb, time, moment, rare) |
| sometimes(expression, adverb, time, moment, continue) |
| from time to time(expression, adverb, time, moment, rare) |
| on occasion(expression, adverb, time, moment, rare) |
| at times(expression, adverb, time, moment, rare) |
| off and on(verb, expression, adverb, phrasal verb, time) |
| periodically(expression, adverb, time, continue, rare) |
| sporadically(expression, adverb, time, continue, rare) |
| every so often(expression, adverb, time, moment, rare) |
| intermittently(expression, adverb, time, continue, rare) |
| once again |
| ever and again(expression, adverb, time, moment, rare) |
| every now and then(expression, adverb, time, moment, rare) |
| infrequently(expression, adverb, time, moment, rare) |
| on and off(expression, adverb, time, moment, rare) |
| once(expression, time, moment, rare, frequency) |
| here and there(expression, idiom, time, moment, rare) |
| at intervals(expression, time, rare, frequency) |