always(总是),usually(通常),frequently（经常） often （经常）sometimes(有时),seldom(不常),rarely（极少）,never（从不） once(一次),twice(两次),等. all the time 100%； almost ,always 90%； generally ,usually 80%； often ,frequently 60-70%； as often as not 40-50%； sometimes ,at times 20-30%； occasionally ,from time to time 10%； hardly ,seldom ,rarely 5%； never 0%.
