Have you ever been in a new situation or place and began to speak like the majority does? While I was in Turkey for a tech transfer project, I heard the Turks speak in a clipped, precise English they'd learned at their university. I must be something of a mime, because I soon caught myself using the same inflections, syntax, and rhythms that they employed while conversing.

Or, if you're from a different region, and you return there for a visit, it won't be long before you revert to the natives' drawl or lilt. We all want to fit in and not to sound funny when we speak is one of the ways we can do it. The same deal applies when authors write their characters' dialogue.

It might come off sounding stilted to some readers while others think it's spot on and believable. Of course, it's easy for authors to exaggerate the lingo and make it inaccessible or too dense to be understood by the readers. Noir and hardboiled genres have their own language that experienced readers and fans might have little or no trouble following while a new reader might give a thumbs down on after slogging through only a few pages.