"A happy family" 用英语说是 "a happy family"。
这是一个普遍的短语，表示一个和睦的家庭。
例句：
A happy family is the foundation of a successful society. (一个快乐的家庭是一个成功社会的基础)
The key to a happy family is strong communication and mutual respect. (一个快乐家庭的关键在于良好的沟通和相互尊重)
A happy family is not an easy thing to achieve, but it is worth the effort. (一个快乐的家庭并不容易获得，但是它值得一试)