星期几的英文：
day of week

参考例句：

What day is today? It's Wednesday.
今天是星期几？今天是星期三。

What day is today, Peter?
今天是星期几，彼得?

What day is today? Today is Monday.
今天星期几?今天是星期一

day是什么意思：
n. 一天；白昼，白天；工作日；时代，时期

Things go on day by day.
事情逐日进行着。

Day by day the situation is improving.
情况在一天天地好转。

Like this, day after day.
就这样，日复一日。

It was a fateful day.
那是个不祥的日子。

Meantime, from day to day they endure.
同时，一天天他们捱了下去。

week是什么意思：
n. 周

The advertizement was run in the paper for a week.
这则广告在报上连续刊登了一个星期。

This week the spotlight is on the world of fashion.
本周引人注目的是时装界。

She has a help in twice a week.
她雇了一个女佣,一周来做两次。

Have a manicure once a week.
一星期修剪一次指甲。

There is to be a polo game next week.
下星期有一场水球比赛。