为什么可以说a quarter past 而不能说a half past

为什么可以说a quarter past 而不能说a half past 7点一刻a quarter past seven可以说成seven and a quarter吗? a quarter past At a quarter past a quarter past a quarter past a quarter past two 为什么四点十五是a quarter past four a quarter past ten,翻译 a quarter past ten汉语 a quarter past ten近义词急! It's a quarter past ten和It‘s half past ten为什么quarter前面加a ,half不加? have sport at a quarter Past four.It's quarter past eight 为什么前一个用a,后一个不用 quarter past quarter past half past 0ne ,前不加a,而 a quarter tohalf past 0ne ,前不加a,而 a quarter to f0ur,前为什么加a? 可以说a quarter an hour吗 可以说a quarter an hour吗