“一年前”翻译成英语应该是a yearr ago 还是one year ago?一月前呢

“一年前”翻译成英语应该是a yearr ago 还是one year ago?一月前呢 on a year ago 还是in a year ago One Year Ago 歌词 英语翻译琳恩-玛莲的one year ago 我要翻译成中文的 he has kept a car since one year ago（对since one year ago 提问） 为什么是one year ago而不是ago one year? half a year ago. 琳恩玛莲 One year ago 中文歌词 one year ago 和a year ago 没有任何区别吗? last year=one year ago A Year Ago Today 歌词 one year ago和one year earlier区别?