What is the author's style in If There Be Thorns by V.C. Andrews?

The book is written in first person but is different from most first-person books in that there are two first-person perspectives - that of Jory and that of Bart. The two generally alternate chapters with Jory acting as the point of view for one chapter and Bart for the next. This would be confusing except that the reader can quickly find the difference in tone that marks the difference between the two characters. For example, Bart's speech is generally very choppy with many half-formed sentences. He might say, "Hate that," rather than offering up a full sentence. Bart also has a tendency to drop the "g" from the end of words so that "going" become "goin." These differences are sufficient and the result is that the reader must decide from the first few words which of the boys is providing the perspective.