Many ancient scripts (notably Linear A from the island of Crete and Rongorongo from Easter Island), have defied deciphering precisely because they cannot be linked to any known language.

• 很多古代手稿（特别是来自克里特岛的A类线形文字和来自复活节岛的朗戈朗戈），难于被破译，因为它们无法与任何已知语言相联系。