The comparative study of dialogues between the original versions, the original versions with French subtitles and the French versions of three sitcoms: Friends, Mad About You and Veronica’s closet demonstrates four categories of translation-adaptation’s artefact: 1) the translation’s gaps due to cultural adaptation, 2) the translation’s inaccuracies that change the characters’ personality, 3) the dialogues’ modifications that affect the initial equilibrium between verbal mediation and visual mediation, 4) the translation’s liberties that can corrupt the narrative texture. Detailed results are presented in analysing the sitcom Mad About You. In comparing the original version with French subtitles and the French version, it shows that the former is more faithful than the latter. Moreover, translation-adaptation is deliberately seen as an opportunity of repositioning for the original version with French subtitles and as a change of target for the French version, by hypothesis of a difference in the French audience request. However, narrative texture corruption and incoherence of the target’s change show that translation-adaptation has not sufficient resources invested in the post-production work.