s = 'there once was a man from nantucket'
vowels = ('a', 'e', 'i', 'o', 'u')
phrase = s.split()

def processWord(word):
    wordtemp = word
    length = len(word)
    for i in range(length):
        letter = word[i]
        if letter in vowels:
            return wordtemp + 'ay'
        else:
            wordtemp = wordtemp[i+1:] + letter
            
def processSentence(phrase):
    sentencetemp = ''
    for word in phrase:
        sentencetemp = sentencetemp + processWord(word) + ' '
    return sentencetemp

finished = processSentence(phrase)
print(finished)