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.
Medieval Hebrew
The need to express scientific and philosophical concepts from Classical Greek and Medieval Arabic motivated Medieval Hebrew to borrow terminology and grammar from these other languages, or to coin equivalent terms from existing Hebrew roots, giving rise to a distinct style of philosophical Hebrew. Many have direct parallels in medieval Arabic. The Ibn Tibbon family, and especially Samuel ben Judah ibn Tibbon were personally responsible for the creation of much of this form of Hebrew, which they employed in their translations of scientific materials from the Arabic. At that time, original Jewish philosophical and theological works produced in Spain were usually written in Arabic, but as time went on, this form of Hebrew was used for many original compositions as well.