Guttural R
Many Jewish immigrants to Israel spoke a variety of Arabic in their countries of origin and pronounced the Hebrew rhotic as an alveolar tap , similar to Arabic '. Gradually, many of them began pronouncing their Hebrew rhotic as a voiced uvular fricative , a sound similar or (depending on the Arabic dialect) identical to Arabic '. However, in modern Sephardic and Mizrahi poetry and folk music an alveolar rhotic continues to be used.
Saadia Ibn Danan
Rabbi Saadiah ben Maimon ben Moshe ibn Danan () (born 2nd half of 15th century in Granada, Spain – died 1493(?) in Oran, Algeria) was a grammarian of Hebrew and Arabic, poet and a halachic authority. He served as a dayan in Granada, and after the expulsion of Jews from Spain settled in Oran. Among his works are rabbinic Responsa, a Talmudic dictionary called "Sepher Arukh," works on Hebrew grammar and Hebrew verse, as well as a Hebrew dictionary written in Arabic. He was the first writer to compare Hebrew metre with its Arabic counterpart.