Abstract
In this paper, I will present a set of basic tools by which we understand the difference of the meanings of words between arguers or between arguments. On the assumption that there is one meaning-theory per person per argument, I will deal with several kinds of elements of an argument including statements and circumstances. Specifically, I will introduce a concept of "grammatical statements" (for an arguer in an argument), which are regarded as unarguable truth. Finally, I will suggest that the difference between meaning-theories can be reduced into the difference between the classes of grammatical statements.