In current Catalan, the verbs semblar and parèixer are two verbs mostly synonyms distributed territorially in a unequal way: While verb parèixer persists in the Valencian Country, in the Balearic Islands and in the northwestern Catalan, the verb semblar coexists with parèixer. Moreover, it has become hegemonic in the centre north of the linguistic domain. However, this distribution is not the one we find in the ancient language, where semblar is a verb relatively uncommon if we compare it with parèixer. In addition, most of the examples for this verb are confirmed in a very small group of works (especially those from the 13th and 15th century). This paper tries to describe the syntactic uses and meanings of verb semblar in ancient Catalan and it also tries to explain the relation that has with parèixer. In outline, we conclude with the fact that the difference founded between both verbs is semantic and the fact that the convergence showed in specific works can be explained as an influence of the Occitan language, as a calque in translations or as a dialectal feature. The study is based in the data obtained from the Corpus Informatitzat de la Gramàtica del Català Antic (CIGCA). Key words: Old Catalan, Gallo-Romance languages, Iberian Romance languages, verb parèixer, verb sembla