The topic of this article is the evolution of auxiliary verbs in Portuguese. Due to the complexity of this question, the article has several objectives:
1. to verify the use of auxiliary verbs in the evolution of European Portuguese;
2. to show the evolution of the concordance of the participle with the direct object or subject;
3. to analyze the relationship between composite time and the resultant construction and its morpho-syntactic characteristics, especially in Old Portuguese;
4. to show the evolution of the temporal/aspectual sense of the compound past perfect in European Portuguese. The research was carried out in the linguistic corpus that allows to make diachronic analyses www.corpusdoportugues.org.