PRESUPPOSITION AND LEGITIMATION STRATEGIES BRAND IMAGE OF AQUA ADVERTISEMENTS IN YOUTUBE

Abstract

This study examines how presupposition and legitimation strategies construct AQUA’s brand image in digital advertisements on YouTube. Using Yule’s (1996) presupposition theory and Van Leeuwen’s (2008) legitimation framework, 31 advertisements from the SehatAQUA channel January 2024 until April 2025 were analyzed through a qualitative descriptive approach. The findings reveal five types of presupposition existential, factive, lexical, structural, and counterfactual with structural presupposition as the most dominant, often appearing in rhetorical questions and grammatical constructions. In terms of legitimation, all four categories authorization, moral evaluation, rationalization, and mythopoesis were identified, with moral evaluation being the most frequent. The study shows that presupposition naturalizes claims as accepted truths, while legitimation justifies them through moral, rational, and cultural grounds. Together, these strategies strengthen AQUA’s credibility and reinforce its image as a trustworthy and socially responsible brand