Teaching is the activity of developing someone's understanding of a subject. It involves patiently attending to what the student understands, how they learn, and why they should learn something. A teacher, then, is someone who understands the subject and knows how to convey the material to the student. How do you help students who are struggling with reading comprehension? Help them understand how to identify the main point. Typically, that involves getting the student to summarize what they're reading. Then, once that is done, I help them work out the details.