This paper presents an experience of using digital text corpora, Base de français médiéval and Bibliothèques virtuelles humanistes, in a research on graphical and lexical markers of represented spoken utterances and citations of written sources. Depending on editing practices and on the state of markup, different queries may be applied to the whole corpora or to some parts of them. The indicators examined in the paper include the relative frequency of the verb dire (‘to say’), the frequency of different punctuation marks used at the borders of the structural elements of represented speech, and marks of written sources citations