Official bip39 word list https://go.bubbl.us/ebe220/f17a?/Bookmarks That is why it is best to create a backup of your seed phrase applying metallic copyright wallet like Coinplate, that are a hundred% chrome steel and BIP39 compatible. For words that have only 3 letters, there is not any 4th letter. As an example https://growthbookmarks.com/story20536954/bip39-mnemonic-code-converter-bip39-converter-an-overview-https-linktr-ee-bip39