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
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