This work analyses the speech-act of arguing as proposed by Linguistic Normative Model of Argumentation (LNMA) with the help of diagrams, examples and basic formalization techniques. The focus is set on one of the most novel issues of LNMA, modal qualification, and the distinction between epistemic and ontological modals. The first conclusion is that employing LNMA in order to analyse and evaluate actual argumentation as it is proposed is too complex to be applied as is. The second conclusion, at a (...) theoretical level, is that the distinction between ontological and epistemic modals is highly problematic in LNMA. (shrink)