Bip39. Although there are actually BIP39 wordlists in languages aside from English, it's strongly not proposed to use non-English words for wallet backups. It might make restoring the wallet hard or extremely hard. This functions due to the fact BIP39 is supported by so many wallet producers. Because of this, https://bookmarklayer.com/story19404057/bip-39-https-linktr-ee-bip39-an-unbiased-view-of-bip-39