For words that only have 3 letters, there isn't a 4th letter. As an example with the word “insert”, there aren't any a lot more letters Later on and thus have to be the word "insert". The word “addict” is during the BIP39 wordlist however you might have employed “addi” https://privatebin.net/?57c491b9cad17a10#2jP1wyi3VUgs8q9BTwvowdFnmCxc6BsRV7dxomBiXrt6