Here is my idea : A statement is truth-apt if and only if it is verifiable by a method agreed upon by the group of persons seeking to verify it.
Statement that aren't truth-apt are matter of communication or narrative.
This isnt question-begging nor self-reffuting. This is only a maxim one can accept or not.
This idea has originated upon from my reading of neo-pragmatism, pragmatism, and on semantic irealism ( An theory of Michel Dummet ).
For example, Xfesfsfsefesf is rgdhfxdrhrx is a kind of statement that isnt probably truth-apt if we accept the maxim.
The apple infront of me is red is a statement that could be verified through the method of "empirical common-sense".
If every person seeking to verify it agree that it is red, it is indeed red.
There could be a "empirical scientific method", a "rethorical method", "mathematical method" etc ...
Ideally, the method must be clear, non-arbitrary in its own framework. We should be able to easily see the result of the method. The method should ideally yield coherent results.