usually的频度为70%左右,译为“通常”、“平常”,即很少例外.例如：
Where do you usually spend the summer holiday?
你通常在什么地方过暑假?
He usually goes to bed at ten o”clock.
他平常10点钟睡觉.
It”s more than usually crowded today.
今天比平时拥挤.
三.often的频度为50%左右,意为“常常”,不如usually那么频繁,表示动作重复,中间有间断.例如：
Mary often weeps when she is alone.
玛丽一个人经常哭泣.
He is often late for school.
他上学经常迟到.
▲Very often语气比often重,常位于句首或句末.例如：
Very often you cannot know one without knowing the other.
如果不知其一,往往不知其二.
He doesn”t go to london very often.
他不常去伦敦.
frequently－－often－－usually－－sometimes--rare--never
（ 从左到右,频率从高到低）．/
你要问的可能是constantly
frequently经常性地.强调经常性.
constantly持续性的动作.强调连贯性.
consistently.一致地