Bip39 Checksum. Although there are actually BIP39 wordlists in languages apart from English, it is strongly not advisable to make use of non-English words for wallet backups. It'd make restoring the wallet challenging or extremely hard. BIP39 specifies a list of 2048 words from which the mnemonic phrase is preferred. https://bookmarkshq.com/story20139792/ian-coleman-bip39-https-linktr-ee-bip39-the-fact-about-bip39-words-that-no-one-is-suggesting