| occasionally(expression, adverb, time, moment, rare) |
| sometimes(expression, adverb, time, moment, rare) |
| on and off(verb, expression, adjective, idiom, adverb) |
| every once in a while(expression, idiom, adverb, time, moment) |
| every so often(expression, idiom, adverb, time, moment) |
| now and then(expression, idiom, adverb, time, moment) |
| on occasion(expression, adverb, time, moment, rare) |
| now and again(expression, idiom, adverb, time, moment) |
| once again |
| sporadically(expression, adverb, time, rare, frequency) |
| at intervals(expression, adverb, time, rare, frequency) |
| at times(expression, adverb, time, moment, rare) |
| from time to time(expression, adverb, time, moment, rare) |
| intermittently(expression, adverb, time, rare, frequency) |
| once in a while(expression, adverb, time, moment, rare) |
| alternately(adverb, variable, vacillating, intermittent, uncertainly) |
| irregularly(adverb, intermittently) |
| variably(adverb, uncertainly, intermittently, alternately, on-and-off) |
| at irregular intervals(expression, idiom, variable, vacillating, intermittent) |
| back and forth(expression, idiom, variably, alternately) |