This document provides an English lesson on using "a" versus "an" correctly. It begins with objectives for the lesson and a pre-test. It then explains that "a" and "an" are used with singular count nouns, and "an" is used if the next word begins with a vowel sound, even if spelled with a consonant like "hour." Examples are provided like "an apple" and "a banana." The lesson emphasizes practicing this rule through an exercise to identify the correct usage of "a" or "an" in sample sentences.