The main goal of this study is to show through the comparative study of the adjuncts décidément and decididamente (and some others) in French and Spanish respectively that a) morphological similarity between two languages is far from being a reliable criterion for translation, as exemplified in: Décidément, quel désastre ! / ¡Desde luego! *¡Decididamente!, ¡Qué desastre! ('It's definitely a disaster!'); b) using elementatry linguistic properties leads to better results. In addition to French décidément, which is the core of the debate, some others cases will also be considered like définitivement, naturellement, incontestablement, indubitablement vs desde luego, decididamente, naturalmente and sin duda. To avoid making arbitrary choices, a good translation of connectives and discursive markers must establish and apply very strict operating rules, as regards syntax and semantics of course, but also contextual and cotextual characteristics.