For words that only have 3 letters, there isn't a 4th letter. One example is with the word “insert”, there are no more letters afterwards and so have to be the word "add". The word “addict” is from the BIP39 wordlist but you might have used “addi” for “addict”. Unlock https://esocialmall.com/story4253667/fascination-about-bip39-english-words