Hebrew alphabet written from right to left. It has 22 letters, five of which use different forms at the end of a word. In the traditional form, vowels are indicated by the weak consonants Aleph (), He (), Vav (), or Yodh () serving as vowel letters, or "matres lectionis": the letter is combined with a previous vowel and becomes silent, or by imitation of such cases in the spelling of other forms. Also, a system of vowel points to indicate vowels (diacritics), called niqqud, was developed. In modern forms of the alphabet, as in the case of Yiddish and to some
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')