For words that only have three letters, there is absolutely no 4th letter. For instance with the word “include”, there aren't any a lot more letters Later on and so need to be the word "add". The word “addict” is during the BIP39 wordlist but you would've utilised “addi” for https://thesocialdelight.com/story4288708/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-definition