French has three types of root polar questions : with est-ce-que, with an inverted clitic, or with a declarative clause. We provide semantic and pragmatic properties that set questioning declaratives clauses (Q-decl) apart from the two other types, showing that their content is a proposition (like with ordinary declaratives) rather than a question. We provide data from a radio talk show, which illustrate their use in conversation, in comparison with that of interrogatives. They are not regular queries but constitute an appeal to the addresse to endorse the proposition. Using logistic regression models, we point out which factors favor the use of Q-decl over the other types.