Abstract
The adverbial al justo originated during the 16th century as a synonym for the short adverb justo. It was used as manner adverbial as well as focus adverb. Its creation was closely connected to the elaboration of written language, e.g. in scientific or technical texts. The pattern «preposition a + article + adjective expressing exactness» was productive with inherited adjectives or those which entered the popular tradition. In the specific case of al justo, it expanded to the former synonym cabal (al cabal), but not to the learned adjectives preciso or exacto. After a short upward trend at the end of the 16th century, the frequency of al justo and al cabal fell during the second half of the 17th century. The marginalization of these adverbials was caused by the competition and selection between several variants forming the paradigm of exactness-adverbs. Al justo, the most frequent variant until the middle of the 17th century, was replaced by justamente. The contrast with French au juste shows that the selection between variants can lead to diverging developments in different languages despite similar initial conditions.