The purpose of the poetry is showing that the person doesent care what the other person says about he/she
1= uno
2= dos
3= tres
4= cuatro
5= cinco
6= seis
7= siete
8= ocho
9= nueve
10= diez
11= once
12= doce
It more clearly explains the overall tension in the city.
He probably did that to: A, make it easier to pick out the more important characters, and B, show that the commoners spoke simple and succinct, whereas the nobles were more educated, and, as such, had a prettier way of speaking. Hope this helps!