Show of Hands

The correct answer: no. The sentence should read, “I hate grammar,” Mark said. “It makes me feel stupid.” Here, “Mark said” functions as a dialogue tag, meaning it tells us who is speaking. In order to attach itself to the dialogue, it needs a comma, not a period. “Mark said” can’t stand alone as its own sentence. Pick up a book and see for yourself :)

Mark said? Mark said what? Is "what" what Mark said? So many confused, I am.

You need a comma after the word grammar, not a period. “I hate grammar,” Mark said. “It makes me feel stupid.”

Following because I like your profile image 😉

Commas, not periods