Bip39 Checksum. Even though there are actually BIP39 wordlists in languages apart from English, it is actually strongly not proposed to employ non-English words for wallet backups. It would make restoring the wallet hard or extremely hard. At its core, a BIP39 passphrase modifies the cryptographic technique of wallet era. https://throbsocial.com/story20973612/bip39-wallets-https-linktr-ee-bip39-bip39-generator-an-overview