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.
Semitic languages
The West Semitic languages significantly reshaped the system. The most substantial changes occurred in the Central Semitic languages (the ancestors of modern Hebrew, Arabic and Aramaic). Essentially, the old prefix-conjugated jussive and/or preterite became a new non-past (or imperfect), while the stative became a new past (or perfect), and the old prefix-conjugated non-past (or imperfect) with gemination was discarded. New suffixes were used to mark different moods in the non-past, e.g. Classical Arabic "-u" (indicative), "-a" (subjunctive), vs no suffix (jussive). (It is not generally agreed whether the systems of the various Semitic languages are better interpreted in terms of tense, i.e. past vs. non-past, or aspect, i.e. perfect vs. imperfect.) A special feature in classical Hebrew is the waw-consecutive, prefixing a verb form with the letter waw in order to change its tense or aspect. The South Semitic languages show a system somewhere between the East and Central Semitic languages.