This document discusses the use of can and can't to express abilities and inabilities. It provides examples of sentences using can to describe things someone or something is able to do, such as "He can sing" and "It can fly." Examples of sentences using can't to describe things someone or something cannot do are also given, like "He can't dance salsa." The document then presents exercises for learners to practice using can and can't in sentences, as well as questions forms using can to ask about abilities. It concludes by noting that can is also used to make offers and requests, such as "Can I help you?" and "Can you please tell me the time?"