For words that only have 3 letters, there isn't any 4th letter. One example is with the word “insert”, there isn't any additional letters afterwards and so needs to be the word "insert". The word “addict” is while in the BIP39 wordlist but you would've applied “addi” for “addict”. gravity https://7bookmarks.com/story18903269/bip39-phrase-generator-can-be-fun-for-anyone