[MMM]

duo797 you were right, too.

I could say

ペンを持っている。 I have a pen.

But if I were asking someone if they have a pen, I would probably say

ペン、ある？Do you have a pen? [or more accurately, Is there a pen?] though there is nothing wrong with ペンを持っている？

I can say 母がいる。 I have a mother, but I cannot say 母を持っている, unless I am physically holding her at the moment.