What language do angels speak?
The language of angels.
It depends on your religion.... A couple of occultists came up with "Enochian" as the language of Angels, whereas in the Bible they spoke Hebrew (which was translated into Greek in the New Testament) but, assuming their existence, they will speak in whatever language the person they are speaking with understands and, thus, no one will ever know their true language (until you die, I suppose).
They will speak the language of the religion they belong to.
So...
Arabic for muslim angels.
Hebrew/Aramaic for Jewish/Christian angels.
Sanskrit for Hindu angels.
... etc.
So...
Arabic for muslim angels.
Hebrew/Aramaic for Jewish/Christian angels.
Sanskrit for Hindu angels.
... etc.