一家人吃年夜饭的英文怎么说

"A family having dinner together" 可以表示一家人吃饭的意思，并不专门针对年夜饭。

关于年夜饭，"A family celebrating New Year's Eve dinner" 或 "A family having New Year's Eve dinner together" 是更准确的表述。

例句：

"My family is having New Year's Eve dinner together at home tonight."
(我家今晚在家里一起庆祝年夜饭。)
"We always have a big New Year's Eve dinner with our relatives to celebrate the new year."
(我们总是和亲戚一起举行盛大的年夜饭来庆祝新年。)

此类表达方式源自英语使用习惯，并不存在固定的定义。