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
Biblical Hebrew phonemes. After a sound shift the letters , could only mark one phoneme, but (except in Samaritan Hebrew) still marked two. The old Babylonian vocalization system wrote a superscript above the to indicate it took the value , while the Masoretes added the shin dot to distinguish between the two varieties of the letter. The original Hebrew alphabet consisted only of consonants, but gradually the letters , , , , also became used to indicate vowels, known as "matres lectionis" when used in this function. It is thought that this was a product of phonetic development: for instance, *bayt ('house')