The incidence of second degree is, according to the definition of Gustave Guillaume, an incidence to an incidence. For instance, lentement (slowly) in Pierre marche lentement (Peter walks slowly) relates to the incidence of marche to Pierre. This definition, although rooted in classical grammar – an adverb cannot be directly related to a substantive, i. e. to a word with internal incidence – is nonetheless fruitful since it eliminates the elements that occur once the first degree incidence has been completed and keeps only the ones that affect this incidence. Among these are manner adverbs and maybe - which is much more surprising - the propositional negation and modal verbs.