you're = you + are
>"You're not alone"
your = possessive
>"Your grammar needs some work."
>It's because they don't read enough.
That's very true, anon. It's also that the only reading they do is on social media, and they see (and mentally copy and later repeat) other people's grammar errors.
plural words written incorrectly with an apostrophe-s (instead of just adding an S for most cases)
lack of commas
lack of hypens
it's (it + is) vs its (possessive)
etc.
I was only a B / C grammar student back in the 1990s. Today's lower standards would make me a fucking genius.