As you can imagine, Grammar Girl is celebrating big time.
Visit her site to send a celebratory e-card to your "favorite language lover or language offender."
She's got got ten grammar myths, a writing contest, t-shirts, and much more. Visit her National Grammar Day post for all the fun.
Go to iTunes to buy her new song, "March Forth." You can even get the sheet music for it. Here's the song. Listen closely to the lyrics for full appreciation!