Show don’t tell is an admonition often given to novice writers and with good reason. There is a tendency to explain, and mostly the explaining has to do with what is going on inside a character’s head. Telling how a character feels will bring the action down every time.

Here is an example: He was determined. He wasn’t going to let himself be talked out of waiting. He knew he had to make contact. Not to do so was unthinkable. He accepted a cup of coffee, but did not say anything when the suggestion was made that he should go back and sleep. He was careful not to reveal his impatience. He could get back tot he checkpoint in 20 minutes if he had to. But he choose to wait. It was getting dark outside.

Boring huh? Compare this to the first graphs of John Le Carre’s THE SPY WHO CAME IN FROM THE COLD. Here, he is showing what we just told.

“The American handed Leamus another cup of coffee and said, ‘Why don’t you go back and sleep? We can ring you if he shows up.’
Leamus said nothing, just stared through the window of the checkpoint, along the empty street.
‘You can’t wait forever, sir. Maybe he’ll come some other time. We can have the polizei contact the agency: you can be back here in twenty minutes.’
‘No,’ said Leamus, ‘It’s nearly dark now.’”

Le Carre uses dialogue as a tool to show this scene. By doing so, he invites the reader directly into the checkpoint overlooking that empty street. He never tells us that Leamus is determined to wait, but we get it and at the same time, we are sucked into the story, wanting to know who he is waiting for and why is he is being so stubborn about it.

Telling cannot be eliminated from story telling; you would end up with a play. But learning when and what to show in a book is a large part of learning to be a writer.