common 多用于指物，侧重很常见，不稀奇。
ordinary 用于物，指每天发生，十分平淡无奇；用于人，指无特别之处，很一般。
common place强调缺少新意。
general 语气强于common，侧重大多如此，很少有例外情况。
usual 指常见常闻和常做的事或举动，强调惯常性。
popular 指适应大众爱好、需要，为大家所公认或接受。
universal 与general同义，但语气较强，侧重对每个人或事物都适用，根本没有例外。
参考例句
1. Attorney General (美国的)司法部长；(英国)检察总长
2. The materials you inquired are our general products. 你询问的材料是我们的常规产品。
3. The general signaled to his officers for the attack to begin. 这位将军向他的军官们发出开始攻击的信号。
英英解释
n.
1. a general officer of the highest rank
2. the head of a religious order or congregation
3. a fact about the whole (as opposed to particular) v.
1. command as a general
2. applying to all or most members of a category or group
3. not specialized or limited to one class of things
4. of national scope
5. prevailing among and common to the general public
6. affecting the entire body
7. somewhat indefinite
8. of worldwide scope or applicability
