These are exercises for simple present. I´m an English techer in Argentina and the simple present is one of the most difficult tenses to teach. So the exerses will help your students to learn in a simple manner. I would like to add that I used them as a test for my second grade students at begginer level. It's very simpe and easy to understand. It is based on the grammar book 'What's up' starter from Logman.