1. always意为"总是,一直"。这是频率最大的词,表示动作重复,状态继续,中间没有间断。如:
Mary is always late for school. 玛丽总是上学迟到。
2. usually意为"通常",表示习惯动作,频率仅次于always,相当于most often。表示除个别情况外,基本上没有变化。如:
He usually gets up at 6 o'clock.
3. often意为"时常,经常",表示动作重复,中间有间断,表示发生的频率比usually要小,但比sometimes要大。如:
I often go to school by bike,but sometimes I go to school by bus.
4. sometimes意为"有时",表示发生的频率最小。
Distinction between "sometimes" and "some time"
He has lunch in the factory sometimes.
I read this story some times.