often,alway.frequently,usually的区别?以上这些词都代表常常,经常,他们有什么区别呢?

always
al-=all全,都；way方式,方法；道路
[5C:lweIz]
adv
总是
He always comes late
他总是迟到.
永远
I shall always remember my first day at school.
我将永远记住我上学的第一天.
usually
usual + -ly
[5ju:VJElI]
adv
通常,经常
usual
[5ju:VuEl]
adj.
通常的; 常 见的; 常有的
平常的,普通的
平时的,平日的
惯例的
He arrived late as usual.
他照常迟到.
It is below the usual size.
它不足一般尺寸.
Tea is considered to be the usual drink of British people.
茶被认为是英国人的日常饮料.
He said all the usual things.
他讲的都是老一套.
often
oft“常常”的异体字
[5Rf(E)n; @) 5C:fn]
adv
多次； 时常
How often do you go there?
你多久去那里一次?
How often you have been abroad?No often,only twice.
你出国几次了?不多,只出去过两次.
经常；通常
Children often dislike homework.
孩子们通常都不喜欢家庭作业.
He often does this.'
它经常干这种事.'
sometimes
some某一+ time时间
[5sQmtaImz]
adv
有时,时不时地,间或
I sometimes think that it is a great mistake.
我有时想这是一个大错.
Sometimes I help my mother in the house.
有时候我帮助妈妈做家务.
Sometimes the 'classroom' is a Mississippi riverboat.
"有时候,教室就在密西西比河上的汽船上."
"Sometimes,when Billy is sick,his older brother has to deliver the newspapers."
"有时毕利病倒了,他的哥哥就得去送报纸."