Worked on enhancing French localization for the phetsims/greenhouse-effect repository, focusing on improving translation accuracy and user experience for scientific content. Addressed pluralization in French for terms such as light sources, target molecules, and bond movements, ensuring grammatical correctness and alignment with scientific conventions. Refined directional terminology and introduced new localization keys to support more natural phrasing in particle-based molecule descriptions. All updates were implemented using FTL and internationalization best practices, delivered in a single, traceable commit to support maintainability. The work demonstrated attention to linguistic detail and contributed to a more accessible and accurate French-language user interface.