The document discusses the differences between gerunds and infinitives. Gerunds are formed by adding "-ing" to a verb and function as nouns. Infinitives are formed by adding "to" before the base form of a verb and also function as nouns. Gerunds refer to real or completed actions, while infinitives refer to potential or unreal actions. The document provides examples of how to use gerunds and infinitives and explains the rules for when certain verbs require a gerund or infinitive.