There are three vowels in Arabic called ḥarakāt (حَرَكَات), which literally means "movements". They can be both short and long. The three long vowels are considered as letters in their full right and feature as such in the alphabet: ā = ا, ū = و, ī = ي. While their corresponding short vowels known as diacritic signs, are symbols written either above or below a particular consonant. There is also a concept of “vowel quality” which can be interpreted as the different ranges of sounds each vowel can produce in conjunction with other letters. Similar to the way “d” can sound very differently depending on the word it’s in, like in “deep” (dēp) or “dam” (dăm). Short Vowels:These three short vowel signs are: Short vowels(fully vocalized text)NameTrans.Value064Eَ◌fatḥaa/a/064Fُ◌ḍammau/u/0650ِ◌kasrai/i/ Fatḥa - (فَتْحَة):a short vowel sound for "a". It is represented by a short diagonal stroke over the consonant it follows in pronunciation, as in دَ pronounced [da]. Ḍamma - (ضَمَّة):a short vowel sound for "u". It is represented by a little looped symbol, like a small wāw (و), over the top of the consonant it follows in pronunciation, as in دُ pronounced [du] or [do] Kasra - (كَسْرَة):a short vowel sound for "i". It is represented by a short diagonal stroke placed under the consonant it follows in pronunciation, as in دِ pronounced [di]. When a letter is followed by a short vowel which is also called ḥaraka (حَرَكَة) in Arabic, which means a "movement", singular of ḥarakāt (حَرَكَات) as mentioned at the beginning of this post. That letter is called a "moving letter" حَرْفٌ مُتَحَرِّك pronounced [ḥarfun motaḥarrik]. However, when it is not followed by any vowel, it is called a “still letter” حَرْفٌ سَاْكِن pronounced [ḥarfun Sākin]. The symbol of "stillness" is called Sukūn. Sukūn – (سُكُون):Sukūn is the absence of a vowel sound. It is represented by a circle above a consonant. In this example, you would say the letter بْ (b) just like in تِبْن pronounced "tibn", which means hay in Arabic. GeneralUnicodeNameTranslit.0652ْ◌sukūn(no vowel with this consonant letter ordiphthong with this long vowel letter) Shadda - (شٙدّة): GeneralUnicodeNameTransliteration0651ّ ّshadda(consonant doubled) When a consonant occurs twice without a vowel sound in between, it is written only once and the Shadda which is similar to a small "w" shape, as shown above, is placed over it e.g مٙرﱠ [marra] which means “he passed by”. It’s worth mentioning here that originally مٙرﱠ [marra] was written مٙرْرٙ [mar-ra] then we had to apply the rule we have just seen by combining the still letters رْ [ar] and the moving letter رٙ [ra] into one letter with the Shadda sign above it رﱠ [ar + ra = rr]. In this case, Shadda is not a vowel sound. It is just a mark that tells you to double the letter it is over. This is not the same as a double letter in English. A double letter in English like the "tt" in bottle does not exist in Arabic. You should also keep in mind that the vowel Fatḥa we had on top of the moving letter is written this time on top of the Shadda sign. This will make us wonder what will happen for the other two short vowels (Ḍamma & Kasra) when combined with Shadda. Well, the rule is pretty simple, the short vowel Ḍamma will be written above the Shadda ـﱡ just like what the vowel Fatḥa did before e.g. يٙمرﱡ [Yamorro] which means “he is passing by”. However, the vowel Kasra is not written as you would expect beneath the consonant it follows. It is written immediately under the Shadda ـﱢ but above the letter, contrary to what we‘ve seen earlier e.g. سِرﱢي pronounced [Sirrī] meaning “Confidential” in Arabic. Furthermore, towards the end of nouns and adjectives, when indefinite, a short vowel can be doubled i.e. two of the symbols for that vowel are placed atop or underneath the letter, and the sound of the word at the end is pronounced “an”, “un”, or “in”. this effect is called nunation or tanwīn تٙنوين in Arabic. Tanwīn al-fatḥa - ـً:Tanwīn al-fatḥa is somewhere between a vowel and a suffix. It is represented by a double short diagonal stroke (double fatḥa) over the top of the consonant it follows in pronunciation, as in the word شكراً pronounced “Shukran”, which means "Thank You" in Arabic. Note: Please notice that Tanwīn al-fatḥa is always written on (ا) as in the previous example. An exception to that is when the final consonant is either the feminine marker, (ة) Taa' MarbuTa as in طالبة [Talibatan] (a female student), or Hamza (ء) as in سماء [Samā-an] (Sky). tanwīn aḌ- Ḍamm - ـٌ:Tanwīn aḌ- Ḍamm is somewhere between a vowel and a suffix. It is represented by a double ḍamma over the top of the consonant it follows in pronunciation, as in the word أٙبٌ pronounced “Abun”, which means "Father" in Arabic. tanwīn al-kasr - ـٍ:tanwīn al-kasr is somewhere between a vowel and a suffix. It is represented by a double Kasra under the consonant it follows in pronunciation, as in the word بِحُبٍ pronounced “biḥobin”, which means "With Love" in Arabic. In Arabic writing, the three vowel diacritics, the sign Sukūn, the sign Shadda, and the tanwīn signs are called شٙكْل [šakl or taškīl] which means "forming". These signs are often left out, at least in part. Sometimes, they are used only to avoid ambiguity in complex texts or for decorative purposes in book titles, letterheads, etc…e.g. تٙعليمُ اللغة العٙربية لغيرِ النّٙاطقِين بهٙا