As an editor, I have been subjected to some of the worst atrocities in the history of the English language -- and I deal with professional writers. I've encountered writers who've attempted to discus the ballet during the election cycle, though most would prefer to discuss the ballot. Iv'e even had a writer who was a lifelong resident of Worchester, though most people eventually learn to spell the name of their home town.
Grammar fails can come in the form of a misplaced (or most often absent) comma, the use of the wrong form of a word (see: your/you're, there/their/theye), or even the use of a word that does not exist -- such as irregardless, or supposably.
Take a look at the epic grammar fails below, and keep your self protected from the long arm of the Grammar Police.
Clarification: Proper Use of Commas Matters.
Um, Maybe I'll Just Order an Omelette Instead.
Pro Tip: Measure Twice, Cut Once.
My Faith in Humanity is Fleeting.
And It's Gone!
Faith Restored (Somewhat).