Waw (letter)
Waw (wāw "hook") is the sixth letter of the Semitic abjads, including
Phoenician wāw 
,
Aramaic waw 
,
Hebrew vav (also vau) ו,
Syriac waw ܘ
and Arabic wāw و (sixth in abjadi order; 27th in modern Arabic order).
It represents the consonant [w] (in Modern Hebrew also [v]) and the vowel [u].
It is the origin of Greek Ϝ (digamma), Υ (upsilon) and Latin F, V and the derived letters U, W, Y.
Hebrew Waw
Hebrew spelling: וָו
Pronunciation in Modern Hebrew
Vav has three orthographic variants, each with a different phonemic value and phonetic realisation:
In modern Hebrew, the frequency of the usage of vav, out of all the letters, is about 10.00%.
Vav as consonant
Consonantal vav (ו) generally represents a voiced labiodental fricative (like the English v) in Ashkenazi, European Sephardi, Persian, Caucasian, Italian and modern Israeli Hebrew, and was originally a labial-velar approximant /w/. It is pronounced, like in Arabic, as a [w] by some Jews of Mizrahi origin.
In modern Israeli Hebrew, some loanwords, the pronunciation of whose source contains /w/, and their derivations, are pronounced with [w]: ואחד – /ˈwaχad/ (but: ואדי – /ˈvadi/).
