The Arabic script has numerous diacritics, which include consonant pointing known as (, ), and supplementary diacritics known as (, ). The latter include the vowel marks termed (, ; , , ).
The Arabic script is a modified abjad, where all letters are consonants, leaving it up to the reader to fill in the vowel sounds. Short consonants and long vowels are represented by letters, but short vowels and consonant length are not generally indicated in writing. is optional to represent missing vowels and consonant length. Modern Arabic is always written with the ijām—consonant pointing—but only religious texts, children's books and works for learners are written with the full tashkīl—vowel guides and consonant length. It is, however, not uncommon for authors to add diacritics to a word or letter when the grammatical case or the meaning is deemed otherwise ambiguous. In addition, classical works and historical documents rendered to the general public are often rendered with the full tashkīl, to compensate for the gap in understanding resulting from stylistic changes over the centuries.
Moreover, tashkīl can change the meaning of the entire word, for example, the words: (دِين), meaning (religion), and (دَين), meaning (debt). Even though they have the same letters, their meanings are different because of the tashkīl. In sentences without tashkīl, readers understand the meaning of the word by simply using context.
Tashkīl
The literal meaning of is 'formation'. As the normal Arabic text does not indicate all aspects of correct pronunciation, the main purpose of (and ) is to provide a phonetic guide or a phonetic aid; i.e. show the correct pronunciation in contexts where such is required, such as for education and poetry.
The bulk of Arabic script is written without (or short vowels). However, they are commonly used in texts that demand strict adherence to exact pronunciation. This is true, primarily, of the Qur'an () and poetry. It is also quite common to add to hadiths (; plural: ) and the Bible. Another use is in children's literature. Moreover, are used in ordinary texts in individual words when an ambiguity of pronunciation cannot easily be resolved from context alone. Arabic dictionaries with vowel marks provide information about the correct pronunciation to both native and foreign Arabic speakers. In art and calligraphy, might be used simply because their writing is considered aesthetically pleasing.
An example of a fully vocalised (vowelised or vowelled) Arabic from the Bismillah:
Some Arabic textbooks for foreigners now use as a phonetic guide to make learning reading Arabic easier. The other method used in textbooks is phonetic romanisation of unvocalised texts. Fully vocalised Arabic texts (i.e. Arabic texts with /diacritics) are sought after by learners of Arabic. Some online bilingual dictionaries also provide as a phonetic guide similarly to English dictionaries providing transcription.
Ḥarakāt (short vowel marks)
The , which literally means 'motions', are the short vowel marks. There is some ambiguity as to which are also ; the , for example, are markers for both vowels and consonants.
Fatḥah
The ( 'opening') is a small diagonal line placed above a letter, and represents a short (like the sound in the English word "cat"). The word itself () means opening and refers to the opening of the mouth when producing an . For example, with (henceforth, the base consonant in the following examples): .
When a is placed before a plain letter () (i.e. one having no hamza or vowel of its own), it represents a long (close to the sound of "a" in the English word "dad", with an open front vowel , not back as in "father"). For example: . The is not usually written in such cases. When a fathah is placed before the letter ⟨⟩ (yā’), it creates an (as in "lie"); and when placed before the letter ⟨⟩ (wāw), it creates an (as in "cow").
Although paired with a plain letter creates an open front vowel , often realized as near-open , the standard also allows for variations, especially under certain surrounding conditions. Usually, in order to have the back pronunciation , the word features a nearby back consonant, such as the emphatics, as well as qāf, or rā’. A similar "back" quality is undergone by other vowels as well in the presence of such consonants, however not as drastically realized as in the case of .Karin C. Ryding, "A Reference Grammar of Modern Standard Arabic", Cambridge University Press, 2005, pgs. 25-34, specifically “Chapter 2, Section 4: Vowels”Anatole Lyovin, Brett Kessler, William Ronald Leben, "An Introduction to the Languages of the World", "5.6 Sketch of Modern Standard Arabic", Oxford University Press, 2017, pg. 255, Edition 2, specifically “5.6.2.2 Vowels”Amine Bouchentouf, Arabic For Dummies®, John Wiley & Sons, 2018, 3rd Edition, specifically section "All About Vowels"
s are encoded , , , or .
Kasrah
A similar diagonal line below a letter is called a ( 'break') and designates a short (as in "me", "be") and its allophones [i, ɪ, e, e̞, ɛ] (as in "Tim", "sit"). For example: .
When a is placed before a plain letter (), it represents a long (as in the English word "steed"). For example: . The is usually not written in such cases, but if is pronounced as a diphthong , should be written on the preceding letter to avoid mispronunciation. The word means 'breaking'.
s are encoded , , , or .
Ḍammah
The ( 'embrace') is a small curl-like diacritic placed above a letter to represent a short /u/ (as in "duke", shorter "you") and its allophones [u, ʊ, o, o̞, ɔ] (as in "put", or "bull"). For example: .
When a is placed before a plain letter (), it represents a long (like the 'oo' sound in the English word "swoop"). For example: . The is usually not written in such cases, but if is pronounced as a diphthong , should be written on the preceding consonant to avoid mispronunciation.
The word ḍammah (ضَمَّة) in this context means rounding, since it is the only rounded vowel in the vowel inventory of Arabic and because its sound is made by rounding the lips in an O shape.
s are encoded , , , or .
Alif Khanjarīyah
The dagger or superscript (), is written as short vertical stroke on top of a letter. It indicates a long sound for which is normally not written. For example: () or ().
The dagger occurs in only a few words, but they include some common ones; it is seldom written, however, even in fully vocalised texts. Most keyboards do not have dagger . The word Allah (, "God") is usually produced automatically by entering . The word consists of + ligature of doubled with a and a dagger above , followed by .
Maddah
The ( 'extension') is a tilde-shaped diacritic, which can only appear on top of an alif (آ) and indicates a glottal stop followed by a long .
In theory, the same sequence could also be represented by two s, as in *, where a hamza above the first represents the while the second represents the . However, consecutive s are never used in the Arabic orthography. Instead, this sequence must always be written as a single with a above it, the combination known as an . For example: .
In Quranic writings, a maddah is placed on any other letter to denote the name of the letter, though some letters may take on a dagger alif. For example: (lām-mīm-ṣād) or (yāʼ-sīn)
Alif waṣlah
The ( 'connection'), or looks like the head of a small on top of an (also indicated by an without a ). It means that the is not pronounced when its word does not begin a sentence. For example: (), but (imshū not mshū). This is because in Arabic, the first consonant in a word must always be followed by a vowel sound: If the second letter from the has a kasrah, the alif-waslah makes the sound /i/. However, when the second letter from it has a dammah, it makes the sound /u/.
It occurs only in the beginning of words, but it can occur after prepositions and the definite article. It is commonly found in imperative verbs, the perfective aspect of verb stems VII to X and their verbal nouns (). The alif of the definite article is considered a .
It occurs in phrases and sentences (connected speech, not isolated/dictionary forms): To replace the elided hamza whose alif-seat has assimilated to the previous vowel. For example: or () 'in Yemen'. In hamza-initial imperative forms following a vowel, especially following the conjunction () 'and'. For example: () 'rise and drink the water'.
Like the superscript alif, it is not written in fully vocalized scripts, except for sacred texts, like the Quran and Arabized Bible.
Sukūn
The ( 'stillness') is a circle-shaped diacritic placed above a letter (). It indicates that the letter to which it is attached is not followed by a vowel, i.e., zero-vowel.
It is a necessary symbol for writing consonant-vowel-consonant syllables, which are very common in Arabic. For example: ().
The may also be used to help represent a diphthong. A followed by the letter () with a over it () indicates the diphthong (IPA ). A , followed by the letter () with a , () indicates .
s are encoded , , or .
The may have also an alternative form of the small high head of (), particularly in some Qurans. Other shapes may exist as well (for example, like a small comma above ⟨ʼ⟩ or like a circumflex ⟨ˆ⟩ in ).
Tanwīn
The three vowel diacritics may be doubled at the end of a word to indicate that the vowel is followed by the consonant n. They may or may not be considered and are known as ( 'nun-ification' , or nunation. The signs indicate, from left to right, .
These endings are used as non-pausal grammatical indefinite case endings in Literary Arabic or classical Arabic (triptotes only). In a vocalised text, they may be written even if they are not pronounced (see pausa). See for more details. In many spoken Arabic dialects, the endings are absent. Many Arabic textbooks introduce standard Arabic without these endings. The grammatical endings may not be written in some vocalized Arabic texts, as knowledge of varies from country to country, and there is a trend towards simplifying Arabic grammar.
The sign is most commonly written in combination with , , , or stand-alone . should always be written (except for words ending in or diptotes) even if is not. Grammatical cases and endings in indefinite triptote forms:
: nominative case; : accusative case, also serves as an adverbial marker; : genitive case.
Dammatan has another shape, , which better resembles how the symbol is handwritten, printed in school books, and in the Quran.
Shaddah
The shadda or shaddah ( 'emphasis'), or tashdid (), is a diacritic shaped like a small written Latin "w".
It is used to indicate gemination (consonant doubling or extra length), which is phonemic in Arabic. It is written above the consonant which is to be doubled. It is the only that is commonly used in ordinary spelling to avoid ambiguity. For example: ; ('school') vs. ('teacher', female). Note that when the doubled letter bears a vowel, it is the shaddah that the vowel is attached to, not the letter itself: , .
s are encoded , , or .
Ijām
The ijām (; sometimes also called ) are the diacritic points that distinguish various letters that have the same backbone form (). In modern Arabic scripts, typically one, two or three dots above or below the letter distinguish it as a different letter. For example, is the letter , whereas with a dot above is the letter . Typically ijām are not considered diacritics but part of the letter.
Early manuscripts of the Quran did not use diacritics either for vowels or to distinguish the different values of the . Vowel pointing was introduced first, as a red dot placed above, below, or beside the , and later consonant pointing was introduced, as thin, short black single or multiple dashes placed above or below the rasm. These ijām became black dots about the same time as the became small black letters or strokes.