The document discusses superlative adjectives, which are used to compare three or more things. It explains that superlative adjectives are formed by changing the adjective to its superlative form, either by adding "-est" for one-syllable words or irregular forms like "best" and "worst". Rules are provided for changing regular adjectives to their superlative forms based on their spelling. Examples are given to illustrate the rules and practice forming superlative adjectives from given base adjectives.