Arabic grammar these vowels are used since they are crucial to the grammar. An Arabic sentence can have a completely different meaning by a subtle change of the vowels. This is why in an important text such as the the three basic vowel signs (see below) are mandated, like the ḥarakāt and all the other diacritics or other types of marks, for example the cantillation signs. Short vowels In the Arabic handwriting of everyday use, in general publications, and on street signs, short vowels are typically not written. On the other hand, copies of the cannot be endorsed by the religious institutes that review them unless the diacritics are included. Children's books, elementary school texts, and Arabic-language grammars in general will include diacritics to some degree. These are known as "vocalized" texts. Short vowels may be written with diacritics placed above or below the consonant that precedes them in the syllable, called . All Arabic vowels, long and short, follow a consonant; in Arabic, words like "Ali" or "alif", for example, start with a consonant: , . Long vowels In the fully vocalized Arabic text found in texts such as Quran, a long following a consonant other than a is written with a short sign () on the consonant plus an after it; long is written as a sign for short () plus a ; and long as a sign for short () plus a . Briefly, = ; = ; and = . Long following a may be represented by an or by a free followed by an (two consecutive s are never allowed in Arabic). The table below shows vowels placed above or below a dotted circle replacing a primary consonant letter or a sign. For clarity in the table, the primary letters on the left used to mark these long vowels are shown only in their isolated form. Most consonants do connect to the left with , and written then with their medial or final form. Additionally, the letter in the last row may connect to the letter on its left, and then will use a medial or initial form. Use the table of primary letters to look at their actual glyph and joining types. In unvocalized text (one in which the short vowels are not marked), the long vowels are represented by the vowel in question: , , or . Long vowels written in the middle