The response effectively uses a variety of sentence structures, enhancing the clarity and detail of the explanation. For instance, complex sentences like "It's an educational platform that offers free courses on a wide range of subjects, from mathematics to arts and humanities," provide comprehensive information smoothly. The use of present simple tense throughout the response ("I use," "It offers," "I discovered") appropriately describes regular actions and general truths, which is suitable for this type of explanatory content. The answer also demonstrates good use of past simple for past events, as seen in "I discovered Khan Academy through a friend."