What is the purpose of asyndeton?
Asyndeton speeds up the pace of a sentence and adds emphasis to a passage.
Asyndeton is the usage of lists without conjunctions such as "and." Without these extra words, the author can effectively quicken the pace of the sentence, which could create a dramatic effect, especially in a suspenseful scene. Without the distraction of "and" between words, the author places more emphasis on the important parts in the list.
On the other hand, syndeton and polysyndeton do use conjunctions between words in a list.
Syndeton is the use of only one conjunction to connect related clauses. "The girl yells, cries, and begs the boy to go" is an example of syndeton.
Polysyndeton would be "the girl yells and cries and begs the boy to go." Syndeton and polysyndeton both slow down the pace of the sentence; they make the sentence sound more uneven and drawn out.
Consider the effect of asyndeton on this sentence:
The girl yells, cries, begs the boy to go...
Can you see how asyndeton changes the pace of the sentence?
Additionally, authors can use asyndeton to emphasize a repeated phrase.
Here's a quote from Winston Churchill that uses asyndeton:
“...we shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our Island...” – Winston Churchill
In this case, Churchill repeats the phrase "we shall" and omits any conjunctions, so that the audience can focus on the important words.
Hope this helps!