This document discusses using infinitive verbs to provide reasons in sentences. It provides examples of sentences using the structure of a main clause followed by an infinitive phrase beginning with "to" to give a reason, such as "I'm going to the bank to cash a check". The document then lists additional examples and exercises for learners to practice forming sentences using infinitives to give reasons. It focuses on common reasons for actions like going, needing, wanting, and studying as main clauses paired with infinitives like "to see", "to buy", "to pass", etc.