For words that have only 3 letters, there is not any 4th letter. For example with the word “incorporate”, there are no far more letters Later on and thus should be the word "insert". The word “addict” is during the BIP39 wordlist however, you would have used “addi” for “addict”. http://zanevnex175.lowescouponn.com/unlocking-the-power-of-bip39-an-extensive-consider-word-lists-and-secure-pocketbooks