两星期用英语可以说为 "two weeks"。其中词语 "week" 来自古英语 "wice"，意为 "四天的时间段"，在中世纪演变为现在的 "week"。例句：

I will be on vacation for two weeks. (我将休假两星期。)

It takes about two weeks for the medicine to take effect. (药物大约需要两星期才会生效。)

I haven't seen you in two weeks. (我已经两星期没有见到你了。)