一年一次是every a year还是once a year 为啥?

一年一次是every a year还是once a year 为啥? 每隔一年在英文中是once every other year还是once every another year? 一年 英语怎么说一年,是 one year 还是 a year一年以前呢,怎么说 ? 一年用英语怎么说应该是an year 还是 A year? a half of year有这样的说法吗?a half of year 是半年还是一年半? A half year later 要怎么翻译啊'''是一年半后还是半年后啊? later that year是指本年还是指下一年? 一年半用英语怎么说?是one and a half years还是one and a half year? 奖学金是一年一次还是一个学期一次 英语次数表达一年一次 once a year用次数+时间段那两年一次呢 两年三次?当时间段是复数时怎么表达? 问一句中译英!越快越好!“一年有四个季节”是There are four seasons in a year.还是There are four seasons of a year,有区别么?越快越好! 英语“这一年”做时间状语是in this year 还是 this year 每年是用every year 还是every years 这两者有什么区别? a year or one year?别人问你来到某个地方有多长时间了,你想回答一年应该是用a year 还是one year呢? 一年后是用a year after 还是 a year late 还是a year later? Then he smiled and told me I would receive an extra thousand pounds a year!出自新概念中,请问（1）a year 表示就是今年一年,还是每年呢,那么每年不是应该用every year吗,（2）另外句子中已经有具体的数字 thousan 1.He often makes a Ner Year R______ every Ner Year's DayR是首字母 是a eight-year-old 还是an eight-year-old