这两个词均为时间频度副词,但表示的时间程度不同。其区别是:1) usually(75%)意为“通常”,着重表示已形成习惯的动作,反义词为unusually. 如:They usually do some shopping on Sunday. 他们通常星期天买东西。What time do you usually have lunch? 你通常什么时间吃午饭?2)often(50%)相当于at times, 意为“时常,经常”。表示常常这样,但不总是这样,反义词为seldom. 如:She often helps her mother with housework. 放学后,她常常帮助母亲做家务。We often go to see our teacher. 我们经常去看望我们的老师。拓展知识:always,usually,often,sometimes,hardly ever和never是英语中最常见的频度副词,他们在句中的位置大致相同:通常放在行为动词之前,系动词be、助动词和情态动词之后.但是他们所表示的含义及频度各不相同.(1) always 的频度为100%,表示动作重复、状态继续,中间没有间断,意思是“总是”、“永远地”.例如:The sun always rises in the east and sets in west.太阳总是东升西落.(2) usually 的频度为70%左右,意为“通常”、“平常”,即很少有例外.例如:He usually goes to bed at ten o’clock.他通常10点钟睡觉.(3) often 的频度为50%左右,意为“常常”,但不如usually那么频繁,表示动作重复,中间有间断.例如:He is often later 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:He doesn’t go to London very often.他不常去伦敦.(4) sometimes 的频度为20%左右,意为“有时”,表示动作偶尔发生.可以位于句首,以示强调.例如:It is sometimes hot and sometimes cold.天气忽冷忽热.Sometimes he does it this way and sometimes he does it that way.他有时这样做,有时那样做.(5) hardly ever 的频度为5%左右,意为“几乎不”、“偶尔”.例如:I hardly ever go out these days.这些天我几乎不出门.(6) never 的频度为0,意为“从来不”、“永不”.例如:My parents are never late for work.我父母上班从来不迟到.