To create tension, dialogue needs to be stretched out. That is, characters should not be immediately responsive.
Sol SteinMost of the time, tough, combative, adversarial dialogue is much more exciting than physical action.
Sol SteinReaders, transformed by film and TV, are used to seeing stories. The reading experience . . . is increasingly visual.
Sol SteinReaders take in dialogue one thought at a time. A frequent mistake of beginners is to combine thoughts, which may be suitable for other forms of writing but not for dialogue. Another mistake is speechifying. Three sentences at a time is tops, yet many beginners write speeches that go on and on.
Sol Stein