Is there a difference between 'pral' and 'prale' in Kreyol? How do I know which is correct?

Pral is a shortened form of prale

So you can say:

Nou pral manje or Nou prale manje

Mwen pral nan fèt la pita or Mwen prale nan fèt la pita

Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words