Do all manga have light novels?The answer is no. Manga has its own creative and narrative style, which can stand alone without the need for a light novel. There are many manga that are based on original concepts and ideas created specifically for the comic format. Some manga may be so unique in their visual storytelling that it would be difficult to translate them into a light novel format. Additionally, the manga industry is vast, and there are many works that are simply not associated with light novels at all.
Do all light novels have manga adaptations?The answer is no. There are a large number of light novels out there, and only a fraction of them get turned into manga. Some light novels might be too niche, or their content might not be suitable for the visual and often more mainstream - oriented manga format. Also, the process of adapting a light novel into a manga requires resources like artists, publishers willing to take the risk, etc., which means that not all light novels will end up as manga.
Do all light novels have to have a title?Light novels usually had a small title that summarized the main plot and character development to help readers better understand the content of the novel. Subtitles could also help the author better plan the plot and structure of the novel to improve its legibility and appeal.