The Structure

Before going into the structure of the novel itself, I think it important to briefly discuss the controversy over ending the novel on the 20th chapter in the American version and leaving in an additional 21st chapter in the UK edition as a way to study how the history and place's audience affected the publication. In the 20th chapter, we see Alex completely reverted to his original state: hungry for sex, violence, and drugs, and that's where the American publication leaves it. In the original additional epilogue of the UK version, the 21st chapter shows Alex all grown up and reflecting on his questionable life choices, having finally learned his lessons. As Burgess himself states in his Introduction, "Americans are tougher than the British and could face up to reality," because he believes in his traditional pessimistic fashion that the American ending is more realistic because people can't truly change (Burgess xiii). Keep in mind the American context of the 1960s: The Vietnam War, a very defeatist point in history. Burgess provides the perfect example of tailoring the aesthetic architecture for his specific audience, so ensure that you recall this shift in ending when deciding how to end your piece. 

The structure of the novel is that it's written in first-person and the 192 pages are separated into 3 sections, consisting of 7 chapters each: 

• Part 1: Alex and his droogs committing crimes and Alex getting arrested.
• Part 2: Alex in prison and getting the Ludovico Technique rehabilitation
• Part 3: Alex getting sent back into the real world

Separating the narrative in this manner divides the three major points of action for the audience: real world, prison, and back to the real world. Also, having 21 chapters is significant because according to numerology, the number 21 is significant in that it represents "the ultimate fulfillment of a long and arduous process of spiritual transformation," which changes meaning depending on which publication you consider ("Numerology Number 21").  It can either be seen as pessimistic and ironic in terms of Burgess's preferred American version, or be representative of Alex's eventual maturing in the original UK publication. Additionally, 21 is the age of maturation and adulthood, which Alex clearly and ironically is not reaching (unless, of course, you're considering the UK's epilogue). Finally, being separated into equal groups of 7 chapters is significant because it represents balance, something that Alex blatantly doesn't possess in his teenage years​.