When the vocative noun is an iḍāfah, the first word is accusative. Keep the second part of the iḍāfah attached to it.
Before calling
Vocative form
What changed
عَبْدُ اللَّهِ
يَا عَبْدَ اللَّهِ
عَبْدُ → عَبْدَ
أُخْتُ هَرُوْنَ
يَا أُخْتَ هَرُوْنَ
أُخْتُ → أُخْتَ
رَبُّنَا
يَا رَبَّنَا
رَبُّ → رَبَّ
رَبِّي
يَا رَبِّي
the written ending remains as shown
Opening interactive controls...
When the vocative noun is an iḍāfah, the first word is accusative. Keep the second part of the iḍāfah attached to it.
Before calling
Vocative form
What changed
عَبْدُ اللَّهِ
يَا عَبْدَ اللَّهِ
عَبْدُ → عَبْدَ
أُخْتُ هَرُوْنَ
يَا أُخْتَ هَرُوْنَ
أُخْتُ → أُخْتَ
رَبُّنَا
يَا رَبَّنَا
رَبُّ → رَبَّ
رَبِّي
يَا رَبِّي
the written ending remains as shown