In Japanese grammar, ordinal numbers are used to indicate the order or position of things in a series. They are formed by adding a suffix to the basic cardinal number. The most common suffixes are « 番目 » (banme) and « 度目 » (dome), which convey a sense of order or iteration. Learning ordinal numbers is essential for understanding and communicating effectively in Japanese, as they are commonly used to describe rankings, dates, positions, and more.