One of the most overlooked conversations in Arabic is the different forms the letter alif can take. Two main forms of an alif are:
- ألف مَقْصُوْرَة – ى
- ألِف مَمْدودَة – ا
They both function as a normal alif in the sense that they elongate the short vowel fatha. But why have both alifs exist? One of the reasons is because of weak letters.
In Arabic there are three weak letters: ا, و, ي. They are weak because they act as long vowels and because they can transform into one another to help in the pronunciation of certain words. ِIn addition, the alif can never be a root letter. So if an alif is visible then the root letter would either be a و or ي. The short vowels and long vowels have a close relationship.
Generally speaking, if a weak letter is preceded by a fatha it will transform into an ا. If it is preceded by a kasra it will tranform into a ي. If it is preceded by a dhamma it will transform into a و.
In the event when a و or ي transforms into an alif is where the different forms of alif become important.
If a و transforms into an alif, it will take the ممدودة form.
If a ي transforms into an alif, it will take the مقصورة form.
So going to the difference between عَلَا and عَلَى. They are both pronounced the same but have different meanings. The ممدودة version is telling us that the root letters are علو which tells us that it is referring to a past tense singular masculine word which means to be high. On the contrary, عَلَى is a preposition which means to be over.
*I am aware that علي is also another possible root letter combination for the verb, but for the sake of brevity I have chosen not to go in more detail. In addition, I am also aware this general rule is not always applicable in every case.