A comparative adjective is a word that compares two nouns, showing the difference in their qualities. It typically ends in "-er" or uses the word "more" before the adjective. For example, in the phrases "taller building" or "more interesting book," the adjectives "taller" and "more interesting" indicate a comparison between two specific items. Comparative adjectives help us express differences in size, quality, or degree. They are essential in everyday language, allowing us to make distinctions, such as saying "John is smarter than" "Mike" or "this car is faster than" "that one."