  Tarski doesn’t give a general formulation of his method. Such a general formulation would not be too illuminating. Instead he helpfully chooses to illustrate his method as it would work for a few languages.  The most basic example he uses, to which about half of his monograph is devoted, is what he calls “the language of the calculus of classes” (LCC). Here is a quick description in more current notation (Tarski uses Łukasiewicz’s Polish notation):