Enhanced descriptions from Syndetics:

Writing Dialogue for Scripts provides expert insight into how dialogue works. It shows what to look out for in everyday speech, and how to apply dialogue in scripts for dramatic effect. Writers learn, on the whole by trial, error and practice, and this book will help guide them on their journey.
A highly practical guide, the book includes much analysis and many examples of scripted dialogue from across different media- from Pulp Fiction to Goodfellas, The English Patient and The Constant Gardner , playwrights Arthur Miller, Caryl Churchill, Michael Frayn, Alan Bennett, Alan Ayckbourn to name just a few, as well as documentaries, TV and radio shows. Chapters deal with how conversation works, naturalistic and stylised dialogue, pace and variation, scripted narration, comic dialogue and presentation.
Updates to this edition includes a look at recent films including The Constant Gardener , and Transamerica , TV shows such as Extras and the award winning play The History Boys. Extended material on storytelling style narration within scripts (suchas Desperate Housewives ) and documentary style dialogue (David Hare's The Permanent Way ) and a new section on 'Highly Stylised Dialogue' dealing with the trend toward dialogue in fantasy sequences.