Sadly, this kid seems about average for what they refer to as spelling and grammar these days. Teachers stopped correcting spelling and grammar errors as it was deemed "more important" for said student to get "the message" correct rather than learning how to write it correctly.
Sad but true.
Way too many people have terrible grammar, even many "journalists" who publish online articles. Go practically anywhere and you'll easily spot mistakes.
Hell, look at the current trend of writing plural words with a fucking apostrophe-s, like writing "anon's" instead of "anons". It's not even close to correct, but so many fucking idiots keep doing it today, and it's only getting worse.