"When to teach this lesson? This lesson is designed to teach to students at a pre-Intermediate level. This means that they have mastered basic language skills and familiarity with plural nouns, a/an, frequency and time. Before starting this lesson, students should have a solid understanding of how to use the present simple tense. They should be starting to use the past and future tenses as well. This lesson can be used to introduce the difference between the articles a/an and the. If you want additional lesson plans and support, including teachers’ notes, be sure to register for a free Off2Class account."