happy的名词形式是happiness，表示快乐，幸福。happy指人在各种状态(如事事顺利)下的愉快、快乐或满足的心理状态。happy在句中可用作定语、表语,必须以人作主语,不用于以it充当形式主语的结构中。
happy造句
1、They swear they are happy.
2、Soak, be soft and happy.
3、No happy eat pistachio nuts.
4、Send our dear ones the happy news.
5、Ah hah, you must be happy.