When I worked slush, it was one of those basic, writing 101 one things that would make me close the doc immediately as it screamed "newbie": incorrect punctuation used within dialogue.
Right: "I once shot a man in Reno just to watch him die," she said.Wrong: "I once shot a man in Reno just to watch him die." She said.
If you're following up dialogue with a speech tag, you end with a comma, close quote, and not with a period; your tag then is a continuation of the sentence and doesn't start with a capital.
Note I said speech tag and not body language. Speech tags include: said, asked, replied, told, screamed, whispered, etc.
Generally speaking, it's not a particularly good idea to use superfluous tags--anything beyond "said" or "asked"--but that's a post for another day.
This is different from body language.
Right: "I once shot a man in Reno just to watch him die." She grinned.
Wrong: "I once shot a man in Reno just to watch him die," she grinned.
You don't grin words, folks, you say them. On occasion I see laughed and sighed used in this way; if you chose to, at most it should be a one word kind of thing as it's very difficult to sigh or laugh an entire line of dialogue; I personally always treat those as body language and not a speech tag for the sake of clarity.
You can, however, interrupt dialogue with body language, and in that case you treat it as once sentence.
Right: "I once shot a man in Reno," she gazed at the gun, "just to watch him die."
Wrong: "I once shot a man in Reno," she gazed at the gun. "Just to watch him die."
What about other punctuation?
Question marks and exclamation points are treated thusly...
Right: "Have you ever shot a man in Reno just to watch him die?" he asked.
Right: "Have you ever shot a man in Reno just to watch him die?" He eyed the gun.
Same rule with exclamation marks, but for now, take them out of your book--you have too many, I promise. You don't need them. I'm not giving them back to you until later. We'll discuss it after supper.
If you want to go further, in most instances you can get rid of your speech tags all together; body language will suffice. But we can talk about that in detail another time.
-------
photo credit: Alex Abian (Also on flickr.com/alexabian) via photopin cc
