We can also use format() to treat vowel harmony. Choose a simplevowel harmony system and show how this might work.

Vowel harmony is a phonological process where the vowels of a word must share certain features. A simple example of a vowel harmony system is found in Finnish language. In Finnish, vowels are divided into two groups: front vowels (ä, ö, y) and back vowels (a, o, u). A word cannot contain both front and back vowels.

Here's how we might use the format() function in Python to handle this:

def vowel_harmony(word):
    front_vowels = "äöy"
    back_vowels = "aou"
    for char in word:
        if char in front_vowels and any((vowel in back_vowels) for vowel in word):
            return "Word does not follow vowel harmony"
        if char in back_vowels and any((vowel in front_vowels) for vowel in word):
            return "Word does not follow vowel harmony"
    return "Word follows vowel harmony"

word = "sauna"
print("{}: {}".format(word, vowel_harmony(word)))

word = "hyvä"
print("{}: {}".format(word, vowel_harmony(word)))

In this code, we define a function vowel_harmony() that checks if a word follows the rules of vowel harmony. We then use format() to print out the word and whether it follows vowel harmony. The words "sauna" and "hyvä" are examples of words that follow and do not follow vowel harmony, respectively.