Many people know the difference between the words "Anbiyaa" & "Rusul". The former being Prophets and the latter being Messengers of Allah (SWT). The first term is general and refers to those people Allah (SWT) chooses to reform people through. Any such person given a particular revelation (book) for guidance becomes a "Rasool" (singular of Rusul). So for example, Zacharia (AS) and his son John the Baptist (AS) were just "Anbiyaa" but Jesus (AS) was a "Rasool" as he brought the Gospel.
Now that all that is out of the way, here are my questions:
1. What is the difference between "Anbiyaa" & "Nabiyeen" which are used in the Quran? What does using one and not the other imply in the meaning of the ayat?
2. Same this goes with "Rusul" & "Mursaleen". What's the difference?
I know that grammatically one word in each pair is a "sound plural" and the other one is "broken plural", but what I am confused about why does Allah (SWT) chooses one instead of the other in different places in the Quran?
I asked a few native Arabs who study the Quran, but did not get a satisfying answer. So if anyone who reads this and knows the answer please let us know.