This document discusses the uses of the verbs "can" and "can't" in English. It explains that "can" is used to express possibility, ability, requests, and permission. The basic structure is subject + can + bare infinitive verb. "Can't" or "cannot" are used to express inability or lack of permission, with the structure of subject + can't/cannot + action verb. Examples are provided to illustrate uses of both "can" and "can't".