a year /one year那个是标准的啊?

a year /one year那个是标准的啊? one year 可以说成 a year 是one year and a half还是a year and a half?为什么? 为什么是one year ago而不是ago one year? one year or two one or two year 的意思 more than a year.more than one year. Two year season we'll make a one year one year later 跟a year later有什么区别 a year or two 还是one year or two 求plus one的A pray for every year歌词 a one year 有这种用法的么? half的用法是 one and a half years 还是one and a half year?half具体的用