Example of dialogue from The Gatehouse Mystery. Note when and where a comma is used.

Mart shrugged.  "We had hardly time to discuss your tidy nature, our mother and I, but Bobby is not mad.  He is wild.  Especially since he was assigned the chore of making his small room navigable again."

Trixie tossed her damp, blond curls.  "Serves him right.  He's wrecked my room plenty of times, and I had to pick up the pieces."

"Well, anyway," Honey put in, "it's good to know that the diamond is in a safe place."

"I'm not at all sure of that," Trixie said worriedly.  Suppose Bobby decides to throw my sewing basket into the trash can for spite?  He's too young to know that I despise the thing."

"Pooh, pooh," Mart said airily. "He probably has no idea that it belongs to you.  From the evidence, I would say that it was relegated to the attic on Christmas night."

"Stop using big words," Trixie said crossly. "It's getting on my nerves.  I wish I knew exactly when I did put that sewing basket up in the attic.  Moths didn't really fly out when you opened it, did they, Mart?"

Common Mistakes

Your and You're.

Your is a possessive as in "This is your book".  You're is the contraction for you are as in "You're going to be sorry for this".

Loose and lose.  

"The dog is running loose."  "He's going to lose the race."