The present text deals with the suffixes of the Galician language that form nouns, adjectives and adverbs. Only those that during the Middle Ages were very productive will be treated and it will prove if they are still in the present. It will be checked if the medieval tendencies had / have continued or have been failed. All these voices will be searched in the Tesouro Medieval Informatizado da Lingua Galega (Medieval Computerised Thesaurus of the Galician Language), later contrasted in the Dicionario da Real Academia Galega (Dictionary of the Royal Galician Academy) that includes the current standard lexicon. The solutions that are not contemplated today will be discussed. And also the current standard solution.