Nas «margens» do «texto»: notas soltas sobre variantes em formas de 'dever' e 'poder'

In this working paper I briefly describe occurrences of constructions with the modal verbs dever ‘must’ and poder ‘can’, verbs which were one of the many subjects of Henriqueta Costa Campos’ linguistic research. The data was retrieved trough the collation of two manuscripts of the same 15th century Portuguese chronicle. I argue that the variants’ contrast, since it evidences distinct alternatives in exactly the same contexts, may provide relevant insights to linguistic diachronic studies.