每周一次两次三次用英文怎么说

每周一次：once a week
每周两次：twice a week
每周三次：three times a week

这是英语中常用的表达方式，来源于英语中对时间频率的表达。

例句：

I go to the gym once a week. (我每周去一次健身房。)
He takes piano lessons twice a week. (他每周上两次钢琴课。)
I have a meeting with my team three times a week. (我每周和团队开三次会。)