For words that only have 3 letters, there isn't any 4th letter. For instance with the word “insert”, there are no a lot more letters afterwards and so need to be the word "add". The word “addict” is during the BIP39 wordlist however , you would have used “addi” for https://gorillasocialwork.com/story20751127/helping-the-others-realize-the-advantages-of-bip39-seed-phrase-mnemonics-generator