Question

A question has come up as to how many letters are in the Arabic alphabet ; some say 28 and others I think say 29 - is that right and if so what is the reason?

Answer

There are differences in the number of letters in the Arabic alphabet.  Some say there are 28 letters, calling the alif with a hamzah on it, an alif.  We know this isn’t the true alif, but a hamzah.  Those that say there are 28 letters don’t include the alif that has no hamzah on it.  Those that say there are 29 letters use the lam/alif combination as a letter, in addition to the hamzah.  This replaces the missing alif and indicates that the true alif occurs as a letter with no vowel and the letter before it has a fat-h on it, in other words, a medd letter.  And Allah knows best.