This document provides information about modal verbs and how to use them correctly. It discusses that modals never take the -s form even with she/he/it subjects. Modals are always followed by base verbs. "Ought to" is the only modal that takes the infinitive form. The document then explains the different uses of specific modals like can, could, would, may, might, should, must, and will. It also provides examples of polite requests using different modals like "may I", "could you", and "would you mind". In the end, it reviews the levels of certainty expressed by different modals.