他正在吃东西用英文怎么说

"He is eating something" 可以用英文表达为 "He is having a meal" 或 "He is having something to eat"。

来源：这是一个常用的英语表达方式，主要用于描述某人正在进餐。

例句：

He is having a meal. (他正在吃饭。)
She is having something to eat. (她正在吃点东西。)
They are having lunch. (他们正在吃午饭。)