Hebrew alphabet . The Arabic letters generally (as six of the primary letters can have only two variants) have four forms, according to their place in the word. The same goes with the Mandaic ones, except for three of the 22 letters, which have only one form. In forms of Hebrew older than Modern Hebrew, כ״ף, בי״ת and פ״א can only be read "b", "k" and "p", respectively, at the beginning of a word, while they will have the sole value of "v", "kh" and "f" in a "sofit" (final) position, with few exceptions. In medial positions, both pronunciations are possible. In
Hebrew alphabet extent Modern Hebrew, vowels may be indicated. Today, the trend is toward full spelling with the weak letters acting as true vowels. When used to write Yiddish, vowels are indicated, using certain letters, either with niqqud diacritics (e.g. or ) or without (e.g. or ), except for Hebrew words, which in Yiddish are written in their Hebrew spelling. To preserve the proper vowel sounds, scholars developed several different sets of vocalization and diacritical symbols called "nequdot" (, literally "points"). One of these, the Tiberian system, eventually prevailed. Aaron ben Moses ben Asher, and his family for several generations, are credited