他重90kg用英语怎么说？这样对吗？在线等！

He weighs 90kgs.

注意,weigh是动词,这里要用第三人称单数. KG要加复数

也可以说
His weight is 90kgs.

weight是名词

weight

单词拼错了
应该是weight
weigh是动词

weigh要改为weight，名词性的。

He weighs 90kg.
或者 His weight is 90kg.
第一个比较地道。