在某人手里的英文

Take English book in his hand.

我们在表达他的另一只手里的时候通常会说：in the other hand或者上文有hand 出现过那么也可以用one来代替hand也就是in the other one

在他的另一只手：in his other hand

因为hand前面另有形容词性物主代词his修饰，所以不能再用定冠词the了。

in his hand The book is in his hand .书在他手里。

in my hand

In his hands