The Mandaic alphabet contains 22 letters and the digraph adu. The alphabet is formally closed by repeating the first letter, a, so that it has a symbolic count of 24 letters:
Vowels
Unlike most other Semitic alphabets, vowels are usually written out in full. The first letter, a, is used to represent a range of open vowels. The sixth letter, wa, is used for close back vowels, and the tenth letter, ya is used for close front vowels. These last two can also serve as the consonants w/v and y. The eighth letter corresponds to the Semitic heth, and is called eh; it is pronounced as a long i-vowel but is used only as a suffix for the third person singular. The sixteenth letter, e, usually represents eat the beginning of a word or, when followed by wa or ya, represents initial u or i respectively. A mark similar to an underscore can be used to distinguish vowel quality for three Mandaic vowels. It is used in teaching materials but may be omitted from ordinary text. It is only used with vowels a, wa, and ya. Using the letter ba as an example:
/bā/ becomes /ba/
/bu/ becomes /bo/
/bi/ becomes /be/
Gemination mark
A dot under a consonant can be used to note gemination, indicating what native writers call a "hard" pronunciation. Sample words include 'there is', 'tooth', 'heart', and 'great'.
Ligatures
The 23rd letter of the alphabet is the digraph adu, the relative particle. In addition to normal joining behavior, some Mandaic letters can combine to form various ligatures:
/kd/, /kḏ/, /ki/, /kl/, /kr/, /kt/, and /ku/
/nd/, /ni/, /nm/, /nq/, /nt/, and /nu/
/pl/, /pr/, and /pu/
/ṣl/, /ṣr/, and /ṣu/
/ut/
Both adu and the old ligature kḏ are treated as single characters in Unicode.
Extensions
Affrication mark
Postclassical and modern Mandaic use many Persian words. Various Mandaic letters can be re-purposed by placing two horizontally-aligned dots underneath. This idea is comparable to the four novel letters in the Persian alphabet, allowing the alphabet to be used to represent foreign sounds :
/g/ becomes /γ/
/d/ becomes /δ/
/h/ becomes /ḥ/
/ṭ/ becomes /ẓ/
/k/ becomes /χ/
/p/ becomes /f/
/ṣ/ becomes /ž/
/š/ becomes /č/, /ǰ/
/t/ becomes /θ/
Ayin
Mandaic ayin is borrowed from Arabic ayin. Unlike in Arabic, Mandaic ayin does not join with other letters.
Each letter of the Mandaic alphabet is said to represent a power of life and light. Mandaeans view their alphabet as magical and sacred. The Semitic alphabet contains 22 letters. In order to bring this number to 24, the number of hours in a day, adu was added and a was repeated as the last letter of the Mandaic alphabet. Without this repetition the alphabet would be considered incomplete for magical purposes.
Unicode
The Mandaic alphabet was added to the Unicode Standard in October, 2010 with the release of version 6.0. The Unicode block for Mandaic is U+0840-U+085F: