The "apron" of a racetrack is an extension of the pavement, and much like Gramma's apron that protected her good house dress from food stains, the track apron is a paved barrier designed to protect the beautifully manicured grassy areas of a racetrack, which are later decimated by someone's victory celebration. The word "apron" is applied much like most of the English language. The "stands" are where people sit. The "pits" have no actual depressed or below ground areas. We drive on parkways, we park in driveways. Your grandson will have ample opportunity to study the English language, as, unless it has changed, it was a required subject every single year of middle, junior high, high school, and college. I took it, I passed it, and now I find few people that I can converse with using it.