Kevin wis right about completely unambiguous translation being impossible, but I think this is probably what you're looking for:
def toEnglish(s):
sentence = s.split(" ")
english = ""
for word in sentence:
if word[:len(word) - 4:-1] == 'yaw':
english += word[:len(word) - 3] + " "
else:
noay = word[:len(word) - 2]
firstconsonants = noay.split("a")[-1]
consonantsremoved = noay[:len(noay) - (len(firstconsonants)+1)]
english += firstconsonants + consonantsremoved + " "
return english