Subtext is the gaps between what they people thinking and what they actually say. Ernest Hemingway called this the ‘Iceberg Theory’ as there is deeper meaning below the surface of the text, in the same way as the bulk of an iceberg floats beneath the surface of the water.
For example, when using dialogue to develop action, the real significance is not what is said but what is meant. People hold back information all the time – they keep secrets, they avoid embarrassment, they twist the truth for good and for bad reasons. US playwright and film director said:
“People may or may not say what they mean, but they always say something designed to get what they want.” (David Mamet)
The subtext reveals more to the reader about your characters than the actual text as you are conveying the motivation behind the character because when subtext conflicts with what a character says or does, it creates tension.
Our challenge as writers is to use this omission and implication to create subtext that the reader will understand. Sometimes your characters may not even know what they truly feel or what they mean and sometimes other characters may totally misinterpret what they mean.
You can create subtext by providing just enough information for the reader to allow them to connect the dots and reach a conclusion. To do this you need to reveal information about the plot or characters without stating it outright. In this way you are foreshadowing what’s to come.
Self-confidence could be pure bluster, evasive replies could be resistance and a seemingly harmless piece of gossip could ignite the fuse that smoulders into a dramatic explosion. A small crisis could carry the seeds that grow into high drama. Knowing what your characters really want and their motivations will strengthen your characterisation and intensify drama in your writing.
I find acting out the story can help with this as it provides the opportunity to explore the character’s thoughts and situations and the different way s tension could be implied to allow the reader to make personal connections.