Your word is turned into a "Pyg Latin" version of the word with the first letter going to the end and "ay" being added.

Pyg Latin

pyg = 'ay'
while True:
    original = input('Enter a word to pygafy (Press Enter to quit): ')
    if original == '':
        print ("It's your perogative to quit.  No judgement here.")
        break
    elif len(original) > 0 and original.isalpha(): #test if string entered is empty and all leters
        word = original.lower()  #stores lowercase version of input
        first = word[0] #first letter in the string
        new_word = word + first + pyg
        new_word = new_word[1:len(new_word)]  #slice of string that removes the first letter
        print (original + " in pyg Latin is " + new_word + ".")
    else:
        print ("That's not a word! Try again.") #Need to figure out how to loop back to the top after an entry