Have you ever wondered where the periods and commas are placed when you’re writing direct and indirect quotations?
The Gregg Reference Manual, Ninth Edition, says, “Periods and commas always go inside the closing quotation mark. This is the preferred American style.”
Examples: She said, “I’ll be there soon.” … “When you are finished,” he said, “we’ll leave.”
Then there is the British style, which places the period outside when it punctuates the whole sentence, and inside when it punctuates only the quoted material.
So, if you’re in the U.S., you’ll probably place your periods and commas inside the closing quotation mark. Here’s more from Purdue Online Writing Lab.
Try to use quotation marks sparingly. There’s a tendency today for people to use them to emphasize far too many words. They often use them in e-mail and on Web sites an a kind of informal way to italicize a word or phrase, but people regularly use them when it’s not “necessary.” See examples at the Gallery of Misused Quotation Marks.