Complex sentence: The concept of the Insular Celtic languages being descended from Hebrew was part of Medieval superstition, but the hypothesis that they had features from an Afro-Asiatic substratum (Iberian and Berber languages) was first proposed by John Morris-Jones in 1899.
Split into simpler sentences: The concept of the Insular Celtic languages being descended from Hebrew was part of Medieval superstition. The hypothesis that the Insular Celtic languages had features from an Afro-Asiatic substratum (Iberian and Berber languages) was first proposed by John Morris-Jones in 1899.