In a sentence containing a Cognate Object, an intransitive verb typically takes a noun phrase that has the same significance or the same morphological root as an object(Sailer 2010, pp. 192). Additionally, the aspects of Italian Cognate Object Construction(COC) are fewer in number compared to the English COC. Moreover, in Italian unergative verbs can take overt-cognate objects, while in English both unergatives and unaccusatives can generally do so. This paper aims to reconstruct COCs based on various theoretical and empirical suppositions through a comparison between the meanings and forms of English and Italian COCs as follows. First, an unergative COC, whose subject`s theta-role is typically "Agent" or "Experiencer", is assumed to be a transitive construction with a concept of absolute transitivity. In English, however, the cognate object appears only in the form of the overt-NP, while in Italian, it is realized as a "null or overt-Cognate Object". Second, an unaccusative COC, whose subject`s theta-role is generally "Patient" or "Theme" is thematically supposed to be an intransitive construction containing its conceptual adjunct at the level of the Conceptual Structure(CS). This is realized as categorial transitivity in English, but intransitivity in Italian at the level of the Grammatical Function(GF).