1) pair指使用时彼此不能分开的两件东西构成的物品，这两件东西可以连在一起，也可以不连在一起，但缺一不可。

He is wearing a pair of glasses.他戴着一副眼镜。

How many pairs of shoes do you have? 你有多少双鞋？

注：a/every/this/that pair of something作主语，谓语动词用单数。

This pair of shoes fits me well.这双鞋我穿很合脚。

A pair of sunglasses is lying on the table.桌子上有一副太阳镜。

She felt as if every pair of eyes in the room was on her.她觉得房子里的每一双眼睛都在看她。

pair也可以指人，相当于couple指的是“同样立场、一起做同样事情或某种关联的两个人，作主语时谓语用复数。

注：a pair of somebody作主语，谓语动词用复数。

The pair were matched for age.这一对是按年龄配成的。

A pair of robbers were trying to kidnap his wife.两个强盗正试图绑架他的妻子。

The pair are looking for sponsorship from local businesses.两人正在寻找当地企业的赞助。

2) couple表示“两个相同的人或物(two things of the same kind)”，指人或物。指夫妻只能用couple，不能用pair。couple表示“夫妇，夫妻”且用作主语时，谓语动词可用单数(视为整体，尤其是当有each, every, only one等修饰时)；也可以是复数(考虑其个体)。

The couple was/were married last week.这一对夫妇是上星期结的婚。

Each couple was asked to complete a form.要求每一对夫妇填一张表。

The couple is/are spending their honeymoon.那对新婚夫妇正在度蜜月。

The young couple are quarrelling with each other.这对年轻夫妻在吵架。(个体)

An old couple from Shanghai is moving in our apartment.一对老夫妇搬进了我们的公寓。(整体)

couple有时指“几个，两三个”，当couple作主语，此时表示复数意义，用作主语时，谓语动词要用复数。a couple of作主语谓语用复数。

He walked a couple of miles.他步行了好几里。

There are a couple of girls waiting for you.有两个女孩在等你。

There are a couple more files to read first.还有两份文件要先读。