| now and then(expression, idiom, adverb, time, moment) |
| sometimes(expression, adverb, time, moment, rare) |
| occasionally(expression, adverb, time, moment, rare) |
| from time to time(expression, adverb, time, moment, rare) |
| now and again(expression, adverb, time, moment, rare) |
| on occasion(expression, adverb, time, moment, rare) |
| infrequently(expression, adverb, time, moment, rare) |
| off and on(expression, adverb, time, moment, rare) |
| irregularly(adverb, vacillating, rarely, infrequently, intermittently) |
| every now and then(expression, adverb, time, moment, rare) |
| once again |
| at times(expression, adverb, time, moment, rare) |
| every so often(expression, adverb, time, moment, rare) |
| on and off(expression, adverb, time, moment, rare) |
| sporadically(expression, adverb, time, rare, vacillating) |
| intermittently(expression, adverb, time, rare, vacillating) |
| periodically(expression, adverb, time, rare, frequency) |
| seldom(adverb, infrequently, occasionally) |
| at intervals(expression, adverb, time, rare, frequency) |
| alternately(adverb, vacillating, infrequently, intermittently, sporadically) |