Abstract
This paper discusses idiomatic expressions like ‘that says it all’, ‘that says a lot’ etc. when used in presenting an argument. These expressions are instantiations of the grammatical pattern that says Q, in which Q is an indefinite quantifying expression. By making use of the pragma-dialectical theory of argumentation and the linguistic theory of construction grammar it is argued that instantiations of that says Q expressing positive polarity (‘it all’, ‘everything’, ‘much’, ‘a lot’, ‘something’) can fulfil the role of an argumentation’s (explicitly expressed) linking premise. Furthermore, an analysis of these expressions as presentational devices shows that an arguer can use them for strategic reasons, i.e. to leave the exact formulation of the standpoint implicit and to present the argument as self-evident. Using these devices derails into fallaciousness when the context offers insufficient clues to reconstruct the standpoint or when the argument does not offer the kind of support that would be required by the specific instantiation of Q. The argumentative function of instantiations of that says Q expressing negative polarity (‘little’, ‘nothing’ and other denials of those expressing positive polarity) is that an antagonist can use them to attack the justificatory power of the protagonist’s argument.