Fractions in Japanese grammar are important to understand when learning the language. They are used to express parts of a whole and are formed by combining a number and a counter. The most common counters for fractions are ”分の” (bunno) for numerator (upper value) and ”分” (bun) for denominator (lower value). Mastering the use of fractions in Japanese will allow you to communicate more effectively when discussing quantities, ratios, and percentages.