(1) Run-on sentences do not run on forever and ever. Wordy sentences are grammatically correct but stylistically suicidal. I could write any random sentence with a thousand different colons and clauses, but if I make sure that I commit no comma splicing or fragmentation, I can keep going on as long as I like without any fear of being nailed by the grammar police, who, most likely, wouldn't be able to pick out any errors anyway since my sentence would be so long and convoluted, a problem we should all avoid like the plague. Here is a genuine run-on sentence: This is a run-on sentence, avoid it.
(2) Please remember how to correctly write dialogue. Please do not write this: "I can't believe it's not sliced bread." She said to Tom. Please, friends. Consider my health.
(3) If you do not know how to use colons, skip 'em. Using semi-colons (;) as commas is a horrific maltreatment of punctuation; a truly appalling act. (See what I mean?) Improper colon use is just as upsetting. Writing "I will pack: cupcake pajamas, my stuffed animal and my worn-out toothbrush" violates colon sanctity.
(4) Definitely remember how to write definitely. Not definately and certainly not defiantly. I hope you wouldn't defiantly do anything, except axe misspellings of definitely from your internal registrar.
(5) Alot is not a word. Neither is already when saying, "I'm already to go!" And alright is atrocious. All right? Good, then.
(6) Passive voice is okay. No great writer accomplished great writing without bucking the great myth that the passive voice is evil. In normal cases, it's good to be active -- but even style must rest a bit.
(7) Refer to oneself properly. Contemporary songs regularly botch the "you and me/you and I" combos. Listen for it. Do not say, "I wish you could throw your voice like me." That's wrong. Instead you ought to say, "I wish you could throw your voice like I (can)." And if you value your life, never pull a stunt like this: "Charlie danced with Jessie and I." Never.
(8) We ought to boycott restaurants with random apostrophe usage. Nothing gives me more delight than mentally correcting restaurants' grammar. Steak 'n' Shake. Not Steak 'n Shake or Steak n' Shake.
(9) The argument over whether we should extend the olive branch to anyways confuses me. You didn't know that World War III is underway in the grammar part of town? It is. They say anyways is wrong: it ought to be anyway. I wouldn't know either way, but we say always and sideways, which makes just as little sense as anyways, anyway.
(10) Grammar geeks drive me insane. They're pointless. They're rude. They make a fuss over things that don't matter a bit and leave normal people in terror, lest they transgress some obscure rule. Grace, friends, grace. Go easy on the lists and vitriol.
Unless you can pull off the adorable-intelligent thing like I can. In that case, fire away. What pet peeves rain on your day?