When writing stories with a number of characters speaking - commonly known as a conversation - each time a different person speaks, a new paragraph is started. For example:
|Ford shouted in Arthur's ear, "Where did he say we were going?"
"He said something about a King," shouted Arthur in return, holding on desperately.
"That's what I said. He just said the King."
"I didn't know there was a the King," shouted Ford.
"Nor did I," shouted Arthur back.
This extract, from the late Douglas Adams' novel Mostly Harmless, shows speech marks used to deliver a conversation effectively.
It is not always necessary to write the name of the person speaking with each piece of text. You can normally rely on the characters talking one at a time, each new line indicating that the other person is speaking.