HAPPENING OFTEN 经常发生的, happening often and to many people or in many places

常见的，普遍的;

Heart disease is one of the commonest causes of death.

心脏病是最常见的死因之一。

Bad dreams are fairly common among children.

小孩做噩梦是常有的事。

It's common for new fathers to feel jealous of the baby.

刚做爸爸的人妒嫉自己的宝宝是很常见的。

It is common for children to be afraid (NOT It is common that children are afraid) of the dark.

儿童怕黑是很常见的。

A LOT 大量的, existing in large numbers

大量的，常见的;

Daisies are very common flowers.

雏菊是很常见的花。

SAME / SIMILAR 相同的/类似的 [usually before noun 一般用于名词前, no comparative 无比较级] common aims, beliefs, ideas etc are shared by several people or groups〔目的、信仰、思想等〕共同的:

people working towards a common goal

朝着共同的目标努力的人们

countries that share a common language

使用相同语言的国家

a theme that is common to all her novels

她所有小说中的共同主题

common ground, facts, features, or beliefs that are shared by people or things that are very different

共同基础，共同的立场:

There is a great deal of common ground between management and trade unions on this issue.

在这个问题上劳资双方有许多共同点。

SHARED BY EVERYONE 大家所共有的, [no comparative] belonging to or shared by everyone in a society

〔社会〕共有的，公共的:

These problems are common to all societies.

这些问题是所有社会的通病。

Joe was chosen as captain by common consent (=with everyone's agreement) .

大家一致同意选乔为队长。

common knowledge, something everyone knows

众所周知的事，常识:

It is common knowledge that travel broadens the mind.

旅行能开阔眼界，这是众所周知的。

the common good, the advantage of everyone

共同的利益:

They work together for the common good.

他们为了共同的利益一起努力。

common practice, a usual or accepted way of doing things

惯例:

It was common practice for families to attend church together.

全家人一起去做礼拜是惯例。

ORDINARY 普通的 [only before noun 仅用于名词前, no comparative 无比较级] ordinary and not special in any way 普通的，平凡的:

common salt

食盐

The twentieth century was called the century of the common man (=ordinary people) .

二十世纪被称为是普罗大众的世纪。

He insists that he is a revolutionary not a common criminal.

他坚持说自己是个革命者，而不是普通的罪犯。

common courtesy / decency / politeness, a polite way of behaving that you expect from people

通常的礼貌（礼节）:

It would be common courtesy to return their hospitality.

对他们的好客作出回应是起码的礼节。

common or garden, [BrE] ordinary

普通的，一般的;

a common or garden dispute

一般的纠纷

make / find common cause (with / against sb), [formal] to join with other people or groups in order to achieve something

（与某人）联合起来〔以达到某种目的〕:

France and Russia made common cause against Britain.

法国和俄国联合起来反对英国。

common touch, the ability of someone in a position of power or authority to talk to and understand ordinary people – used to show approval

平易近人的品质〔含褒义〕:

He's made it to the top without losing the common touch.

他虽已晋升高位，却仍然不失亲民本色。

SOCIAL CLASS 社会阶层, [BrE old-fashioned] an offensive word used for describing someone from a low social class

粗鄙的，劣等的〔对下层社会成员的冒犯用语〕

have sth in common (with sb), to have the same interests, attitudes etc as someone else

（与某人）有共同之处:

I found I had a lot in common with these people.

我发现自己和这些人有许多相同之处。

four women with almost nothing in common

几乎没有任何共同点的四个女人

have sth in common (with sth), if objects or ideas have something in common, they share the same features

（与某事物）有相同的特点:

The two games have much in common .

这两个游戏有许多相同之处。

in common with sb / sth, in the same way as someone or something else

与某人/某物一样:

In common with a lot of other countries, we're in an economic recession.

同许多国家一样，我国也处在经济萧条时期。

[C] a large area of open land in a town or village that people walk or play sport on

〔城镇或村庄里的〕公用草地:

Boston Common

波士顿公用草地