Readers 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 SteinI see manuscripts and books that are spoiled for the literary reader because they are one long stream of top-of-the-head writing, a writer telling a story without concern for precision or freshness in the use of language. Some of this storytelling reads as if it were spoken rather than written, stuffed with tired images that pop into the writer's head because they are so familiar. The top of the head is fit for growing hair, but not for generating fine prose.
Sol Stein