Herufi za Kiarabu, kama tunavyozijua leo, zinaundwa na mistari na nukta. Nukta hizo huitwa i'jam. Maandishi ya Kiarabu ya zamani hayakuwa na nukta hizo, bali yalikuwa na mistari tu.

The Arabic letters, as we know them today, are made up of lines and points. The latter are called i'jam. The ancient Arabic script did not have them, but consisted of strokes only.

Kuongezwa kwa nukta za kutofautisha kwenye maandishi matupu ya mistari kulisaidia kutofautisha herufi mbalimbali ambazo zingeweza kuchanganyikana kwa urahisi.

The addition of diacritical points to the plain writing of strokes helped to distinguish the various letters which could be easily mixed up.

Mfano: XXX XXX Bila nukta, neno hili haliwezi kutambulika kwa urahisi. Kwa kutumia i'jam, herufi za neno hili zinaweza kutofautishwa kwa urahisi.

Example: XXX XXX Without dots this word cannot be easily recognized. With i'jam, the letters of this word can easily be distinguished.

Ingawa alama za i'jam (nukta za kutofautisha herufi) zilikuwa tayari zinajulikana kabla ya Uislamu, zilitumika kwa nadra. Nakala za awali sana za maandishi ya Qur'ani (na maandishi ya Kiarabu kwa ujumla) hazikuwa na alama hizi. Inaonekana zilianzishwa katika maandishi ya Qur'ani wakati wa Khalifa wa tano wa Ki-Umayya, 'Abd al-Malik bin Marwan (66-86H/685-705), na wakati wa utawala wa Al-Hajjaj huko Iraq, wakati Waislamu wengi zaidi walipoanza kusoma na kujifunza Qur'ani, baadhi yao wakiwa hawakuijua vizuri, na wengine wakiwa wa asili isiyo ya Kiarabu. Inasemekana kwamba tabi'i maarufu Al-Du'all ndiye wa kwanza kuweka nukta hizi katika maandishi ya Qur'ani.

Although the i'jam (diacritical points) were already known in pre-Islamic times, they were rarely used. The very early copies of the Qur'anic manuscripts (and Arabic writing in general) did not have these signs. They were apparently introduced into the Qur'anic script during the time of the fifth Umayyad Caliph, 'Abd al-Malik bin Marwan (66-86H/685- 705) and the governorship of Al-Hajjaj in Iraq, when more and more Muslims began to read and study the Qur'an, some of whom did not know much of the Qur'an, and others were of non-Arab origin. It is said of the well-known tabi'l Al-Du'all that he was the first to introduce these points into the Qur'anic text.