Install Bip39 Some words are shorter than four letters, like the word “act”. Other words are extended than four letters, such as “summary”. One list of mnemonic may be used to produce many addresses. This technique of generating account was introduced in BIP32 & BIP39 long time in the past. https://thebookmarkid.com/story18686292/bip39-list-github-5-essential-elements-for-bip39-word-list