always 100%
I always go to the library to study before exam.
我考试前都会去图书馆读书。
usually 90%
这个副词代表发生的频率非常高，等于 most of the time, generally, normally, as a rule，是「通常」的意思。
Jenny usually plays golf on Sundays.
Jenny 通常礼拜天都会去打高尔夫球。
I normally wouldn’t agree, but I’ll make an exception this time.
我通常不会答应，但这次我可以破例。
often 70%
这个字的中文也跟 usually 一样，都是「往往」、「通常」，但它发生的机率比 usually 低。它的同义词还有 frequently。
I often take a nap during breaks.
我经常在休息时间小睡片刻。
My company frequently holds conferences at that hotel.
我的公司经常在那间饭店举行会议。
sometimes 50%
这个字意指发生频率大约「一半一半」，大致上等于 now and again/then, from time to time。
We all make mistakes sometimes.
我们有时都会犯错。
My sons play basketball after school now and then, but not as often as they used to.
我的儿子们有时放学后会去打篮球，但频率不如以往。
occasionally 30%
Occasionally, things don’t go as planned.
事情有时候就是会不如预期。
seldom 10%
We seldom go to the movies.
我们很少去看电影。
hardly 5%
这个字常常被人误用，它不是 hard 的副词，它的意思是「几乎不」，同义词还有 rarely。
After 10 years, I could hardly recognize her.
经过了十年，我几乎无法认出她。
She rarely talks about her past.
她几乎不曾提起她的过去。
never 0%
He never breaks his promises.
他从不食言。
