Punctuating dialogue correctly can trip up even the most talented author. From the outside, it can appear that the dialogue punctuation rules are a black box of contradictions.
Many authors shy away from the nitty-gritty of writing and feel that the grammar rules of punctuating dialogue is something an editor or proofreader should fix. They are wrong. The grammar rules regarding dialogue are the basic building blocks for your writing; if you have professional pride in your work, then you should be getting it right.
On a more pragmatic level, no one will care as much about your book as you do. Yes, professional editors and proofreaders will fix errors, but the more errors there are, the greater the chance those pesky buggers will slip through the editing net.
The best way to explain the rules of punctuating dialogue is by example. We will use the following section of dialogue to illustrate the steps required to properly punctuate:
Hi have you seen my cat said Bob. No said Bill I have no idea where your cat is. If you see my cat will you let me know questioned Bob looking sad. Of course replied Bill with a tone of concern.
The first rule is: new speaker, new paragraph.
This is easy to apply. Each time a new speaker talks, you place the line of dialogue in a new paragraph, with the first line indented.
We can see how this applies to our example:
Hi have you seen my cat said Bob.
No said Bill I have no idea where your cat is.
If you see my cat will you let me know questioned Bob looking sad.
Of course replied Bill with a tone of concern.
Next, we look at adding quotation marks.
Our next rule says that all dialogue should be placed within a pair of quotation marks.
For books to be published in the States, use as your default the double quotation marks (“ and ” which are the opening quote mark and the closing quote mark, respectively), which is our default for this book. [NOTE: For books to be published in England, use single (‘ and ’) quotes as your default.] However, keep in mind when reporting dialogue inside dialogue, to use the opposite of your default when repeating someone else’s words.
Here’s our example with quote marks added:
“Hi have you seen my cat” said Bob.
“No” said Bill “I have no idea where your cat is.”
“If you see my cat will you let me know” questioned Bob looking sad.
“Of course” replied Bill with a tone of concern.
Now, it’s time for punctuation.
When writing dialogue you will often use tags. These are verbs that link the spoken words with the remainder of the sentence. Commonly used tags include said, asked, replied and many more. Without going into technical detail, to correctly punctuate spoken words from their tags, you must link them using a comma. If you use a period, the sentence is broken, and it no longer makes sense.
If we look at the second line of our example, we see:
“No” said Bill
This is a single sentence and, therefore, should end with a period, giving us:
“No” said Bill.
The tag in this sentence is said, and this must be connected to the corresponding dialogue. If you added a period at the end of the spoken word, it would disconnect the tag from the dialogue, breaking up the complete sentence, which is incorrect:
“No.” Said Bill. [WRONG]
Instead, we must link the spoken word and its tag with a comma.
This gives us:
“No,” said Bill. [CORRECT]
If we apply this to the full example, we get:
“Hi, have you seen my cat?” said Bob.
“No,” said Bill. “I have no idea where your cat is.”
“If you see my cat, will you let me know?” questioned Bob, looking sad.
“Of course,” replied Bill, with a tone of concern.
Please note that in the first and third lines we have used a question mark instead of a period since both are questions asked.