Answer
Yes, Rossellini was a screenwriter. His first screenplay was for a film called "La Nave Bianca" (1940), which he also directed. He also wrote the screenplays for several of his own films, including "Stromboli" (1949), "Europa'51" (1952), and "La Dolce Vita" (1960). Rossellini's screenplays are often characterized by their realism and their focus on social issues.