In Modern Israeli Hebrew, א (’, “alef”) represents either a glottal stop (/ʔ/), or has no pronunciation besides that of the vowel attached to it. The pronunciation varies from group to group.
א (’, “alef”)—along with the other guttural letters, ע (ʿ, “ayin”), ר (r, “resh”), ה (h, “he”), and ח (ḥ, “hḥêṯ”)—cannot receive a dagesh (the dot in בּ (b, “bet”), which can appear in most other Hebrew letters), although there are rare examples where the Masoretes added a dagesh to it.
א (’, “alef”) is sometimes used to denote a vowel (usually /a/) in words of Aramaic and Arabic origin, in foreign names, and in some other borrowed words.