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.
- I'm trying not to get into (= start) the habit of always having biscuits with my coffee.
- I used to swim twice a week, but I seem to have got out of (= ended) the habit recently.
- I was taught to drive by my boyfriend and I'm afraid I've picked up (= caught) some of his bad habits.
- I'm trying to get him to break (= end intentionally) the habit of switching on the TV when he comes home at night.
- I don't mind being woken up once or twice in the middle of the night by my flatmate so long as she doesn't make a habit of it (= do it frequently).
- I'm not really in the habit of looking at (= I don't usually look at) other people's clothes, but even I noticed that awful suit!
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
- In my country, it's the custom (for women) to get married in white.
- He left the house at nine exactly, as is his custom.
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.
- It's bad manners to eat with your mouth open.
- It's considered good manners in some societies to leave a little food on your plate.
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
practice : 常指习惯性的做法或行为。
- What can European companies learn from Japanese business practices?
- It's common practice in the States to tip the hairdresser.
- This is a cruel practice that should be banned immediately.
- What is standard practice (= what is usually done) in a situation like this?
- Newspaper editors have agreed to a new code of practice on the invasion of privacy.
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.
- Convention dictates that it is the man who asks the woman to marry him and not the other way round.
- In many countries it is the/a convention to wear black at funerals.
- an artistic convention
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.
- Switzerland has a long tradition of neutrality.
- 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.
- We decided to break with tradition (= not behave as usual) this year and go away for Christmas.
- According to tradition, a headless ghost walks through the corridors of the house at night.