habit、custom、manners、usage、practice、convention与tradition这些名词均含有“习惯、风俗、传统”之意。
habit : 侧重于自然养成的，不易去掉的个人习惯。
I always buy the same brand of toothpaste out of (= because of) habit.
我出于习惯总是买同一个牌子的牙膏。
I'm trying not to get into (= start) the habit of always having biscuits with my coffee.
我尽量避免养成喝咖啡时总是吃饼干的习惯。
custom : 指一个国家、一个民族、一个地区或一个社会的习惯、行为方式或风俗习惯。也可指个人的习惯。
a local/ancient custom
当地的／古老的风俗
In my country, it's the custom (for women) to get married in white.
在我国，女子结婚穿白衣是一种习俗。
He left the house at nine exactly, as is his custom.
他9点准时离开了家，这是他的习惯。
manners : 指在某一时期或某一团体中盛行的社会礼仪或社会风俗模式。
He needs to be taught some manners.
他需要学些礼仪。
It's bad manners to eat with your mouth open.
张着嘴吃东西是不文雅的。
It's considered good manners in some societies to leave a little food on your plate.
在某些社会中，人们认为盘中剩下少许食物是礼貌的表现。
usage : 指持续时间长，为很多人公认采纳的惯例、习俗。
the dictates and usages of polite society
上流社会的规定和惯例
practice : 常指习惯性的做法或行为。
What can European companies learn from Japanese business practices?
欧洲公司能从日本工商业的做法中学到些什么呢？
It's common practice in the States to tip the hairdresser.
在美国通常要给理发师小费。
This is a cruel practice that should be banned immediately.
这是个残忍的习俗，应该立即禁止。
convention : 多指约定俗成的行为方式规则或公认的标准，或指艺术上公认的技巧。
They defied/flouted/broke with convention by giving up their jobs and becoming self-sufficient.
他们离经叛道，放弃了工作，开始过自给自足的生活。
Convention dictates that it is the man who asks the woman to marry him and not the other way round.
根据习俗，应由男人向女人求婚而不是反过来。
tradition : 广义指世代相传的伦理、行为规范和生活方式，特指因长久奉行而几乎具有法律效力的习惯、习俗，侧重历史意义。
Fireworks have long been an American tradition on the Fourth of July.
7月4日国庆日放焰火长期以来一直是美国人的传统。
Switzerland has a long tradition of neutrality.
保持中立是瑞士长期以来的传统。
There's a tradition in our office that when it's somebody's birthday, they bring in a cake for all of us to share.
我们办公室有个传统：当有人过生日时，就会带蛋糕来跟大家一起分享。