Contact
The fastest way to reach GrammarNook is email: contact@grammarnook.com. Every message goes directly to the person who researches and writes the entries on this site, not a support queue.
Good reasons to write in: a word-form entry that looks wrong or out of date, a verb or noun or confusable pair you searched for and couldn't find on the site, a broken link, or a question about the cheat-sheet bundle or a purchase. Corrections in particular get looked at directly and are the single most useful kind of message this address receives — if an etymology, a past-tense form, or a usage note is inaccurate, that's worth fixing quickly.
Response times vary since this is a small, independently run project rather than a staffed help desk, but every email does get read.