can you support this claim ?
Sure!
I will try to summarize it as simple as possible since really it could be its own book.
We observe that things are made up of stuff. I am going to call that stuff "matter"
We observed through science that everything is composed of the basic matter: atoms
The order of these atoms is what determines what the thing is.
This order we call the form.
So, everything is matter and form that we can observe. I will use the word "observe" to mean any stimulation of the senses.
Now this distinction of matter and form is a distinction of reason. We see the order of the matter and the matter itself. That is how we recognize what the things is. That means that matter and form cannot be seperated in reality. It would no longer be what it is if they did somehow seperate.
But beause the distinction comes from reality, the being of matter and the being of form must be different.
The conclusion then:
These are two beings that coexist in the same thing, but are not fundamentally similar. Being is not a univocal term, it does not have only one meaning. The being of matter is not the same as the being of form. They both exist but not as the same thing, but in the same thing
What we say of the form itself, we cannot say of the matter itself and vice versa.