为什么恭喜用英语说都是congratulations,而不是congratulation 恭喜你成年了英文

祝贺一个人成年用英语怎么说我要一个完 祝贺一个人成年Congratulations on a man of adulthoodCongratulations for you have been a adult祝你已经成zhidao为一个成年...