ENThis paper presents a comprehensive comparative analysis of the functions of the present, past and future perfect forms in standard Latvian and Lithuanian based on two complementary types of data: the typological questionnaire devised for the study of the perfect for the EUROTYP project and the Lithuanian-Latvian parallel corpus. We analyse the data qualitatively as well as quantitatively and demonstrate that the two Baltic languages show both similarities and important differences in their perfect grams. While the Present Perfect in Latvian clearly shows a higher degree of grammaticalisation than in Lithuanian, manifested in the frequency of use, obligatoriness and functional extent, the differences between the two languages in the uses of the other tenses of the perfect are more intricate and largely pertain to the expression of modal and discourse-oriented functions. Keywords: aspect, Baltic, discourse modes, Latvian, Lithuanian, parallel corpus, perfect, pluperfect, questionnaire, tense. [From the publication]