Start a new paragraph every time a character speaks and begin the paragraph with an open-quote mark. When using quotation marks to denote dialogue, you mark the end of a paragraph with a close-quote mark whenever the next paragraph's speaker changes. If a character speaks during two or more consecutive paragraphs, all paragraphs except the last one in which this character speaks should not have a close-quote mark. By doing this consistently, you ensure that your readers can understand who is speaking when.
Mark only the words the characters are speaking with quotation marks. Do not put your quotation marks around words which tell which character is speaking, such as "Tom said" --- these phrases are called speech tags. If you include a speech tag in the middle of a dialogue line, stop and restart your quotation marks when the character's dialogue begins again.
Lead into and out of quotations with commas unless you're beginning a paragraph with dialogue. If your speech tag comes before your quotation, place a comma after the tag. If the speech tag comes after the quotation, place a comma inside the close-quote mark and before the tag. Leave out this comma if you have a question mark or exclamation point at the dialogue sentence's end.
Capitalize the first letter of the quotation if the quotation contains a complete sentence. For example, if writing the line, "Tom asked, 'Are you going to the movies?' " you capitalize the first letter of the quotation even though it is not the start of your sentence.
Place sentence-ending punctuation inside the close-quote mark.