I am working on a code, but I keep getting a KeyError at line 71.

Traceback (most recent call last):
File "main.py", line 71, in
pronunciation += vowels_dict[key]
KeyError: 'l'

Why do I keep getting this error, and how do I fix my code to get rid of this error? Even when I got rid of that line, it gave me a KeyError at line 67.

Traceback (most recent call last):
File "main.py", line 67, in
pronunciation += consonants_dict[key]
KeyError: 'a'

My code is below:

valid_letters = 'aeioupkhlmnw'
invalid_letters = 'bcdfgjqstvxyz'

pronunciation = ''

consonants_dict = {
'p':'p',
'k':'k',
'h':'h',
'l':'l',
'm':'m',
'n':'n',
'w':'w',
'aw':'w',
'iw':'v',
'ew':'v',
'uw':'w',
'ow':'w'
}

vowels_dict = {
'a':'ah-',
'e':'eh-',
'i':'ee-',
'o':'oh-',
'u':'oo-'
}

vowels_no_hyphen_dict = {
'a':'ah',
'e':'eh',
'i':'ee',
'o':'oh',
'u':'oo'
}

vowels_dict_capitalized = {
'A':'Ah-',
'E':'Eh-',
'I':'Ee-',
'O':'Oh-',
'U':'Oo-'
}

vowel_pairs_dict = {
'ai':'eye-',
'ae':'eye-',
'ao':'ow-',
'au':'ow-',
'ei':'ay-',
'eu':'ehoo-',
'iu':'ew-',
'oi':'oy-',
'ou':'ow-',
'ui':'ooey-'
}

hawaiian_word = input('Enter a hawaiian word: ')
hawaiian_word = hawaiian_word.lower()

for i in range(len(hawaiian_word)):
if hawaiian_word[i] in valid_letters:
for key in hawaiian_word:
if hawaiian_word[i] in consonants_dict:
pronunciation += consonants_dict[key]
elif hawaiian_word[0][0] in vowels_dict:
pronunciation += vowels_dict_capitalized[key]
elif hawaiian_word[i] in vowels_dict:
pronunciation += vowels_dict[key]
elif hawaiian_word[i-2] in vowels_dict:
pronunciation += vowels_no_hyphen_dict[key]

if hawaiian_word[i] in invalid_letters:
print('Invalid word, ' + hawaiian_word[i] + ' is not a valid hawaiian character.')


print(hawaiian_word.upper() + ' is pronounced ' + pronunciation)