The document discusses modal verbs, which express the writer's attitude towards abilities, requests, and intentions. It categorizes different types of modals, including 'can', 'will', 'would', 'could', 'shall', 'should', and 'may', providing examples for each to illustrate their uses. The authors, Brianna Boholst and Alexa Paulin, summarize the functions and applications of these modals in communication.