Absence of vowels
Sookoon ــْـ
Sometimes a letter carries no vowel. Such a letter will be pronounced with the letter preceding it, both together forming a syllable. This means that an unvowelled letter is never found at the beginning of a word as it will be impossible to pronounce it with no preceding letter to link it to. The absence of a vowel is indicated by placing a tiny circle ــْـ on the unvowelled letter.
Examples include:
اَلْ : pronounced as al
مِنْ : pronounced as min
كُلْ : pronounced as kul (the u being like that in full)
Final vowels
A vowel (whether single or double) on the last letter of a word is not pronounced when it is followed by a pause, like at the end of a sentence. In other words, it is treated like it is unvowelled. اَلْوَلَدُ is read as الولدْ when paused on.
This is different with ــًا, as it turns into the long vowel ــَا instead. ولدًا is therefore read as ولدَا when paused on.