Moses ofcourse spoke Egypcian as he grew up in the Farao’s Household. Afther that he fled into the dessert and lived with some beduins for a couple of years. There he should have picked up some sort of Arabian. When he came back to Egypt he communicated mainly with the Jewish people, thus he should have know or learned some Hebrew to.
AFAIK, Exodus 2:10 does say that “
when the child grew up, [the child’s mother] brought him to Pharaoh’s daughter, and he became her son.” This does not necessarily mean though that he was reared in the royal court like a prince, but I did hear it possible that he may have been a ‘child of the
kap’, that is, he could have been educated in the manner of foreign princes taken in charge by the Pharaoh. The
kap was a sort of institution at the royal court where children of both Egyptian and foreign nobility were brought to be raised in a manner that was meant to ensure future loyalty to the Egyptian king. ‘Children of the
kap’ were usually placed in positions of standing once they reached adulthood, although these rarely included higher positions within the government. This most likely is the manner in which he acquired the knowledge necessary to serve in the royal administration. So unlike Hollywood’s ‘crown prince Moses’ the other alternative here is that Moses was a sort of official under the service of the king (and probably not a high-ranking one at that; cf. Exodus 2:14), though we couldn’t know for certain as the Bible is silent in this regard.
Yet another interpretation for the record focuses on the words “
when the child grew up,” or in the Hebrew,
wayiḡədal hayyeleḏ “
and the child got big.” We oftentimes assume that this only refers to the point when the baby was weaned, though in other instances in the Bible another word for ‘weaned’ is used (cf. Genesis 21:8, where it speaks of Isaac: “
he got big and was weaned”). In this idea, Moses is brought to the court when he is old enough to at least know who he is - which probably also includes the knowing the slaves’ language!
And, it ain’t really Bedouins (there’s Cecil B. DeMille’s ghost again!

) that Moses visited but Midianites. Unfortunately we know little about them - where they exactly lived (they are mentioned as living in diverse areas, which leads some to propose that ‘Midianite’ is a catch-all term for different groups of ethnic peoples) and what language they spoke.
For the record, before the advent of Islam there was actually a variety of languages and dialects spoken in the Arabian Peninsula. At the south for example you have the
Old South Arabian languages (all now extinct):
Sabaean,
Minaean,
Qatabanian, and
Hadhramautic. At north you have
Ancient North Arabian and various related dialects, the only surviving descendant of which is
Classical Arabic.
I do think the Hebrews maintained their own language during their captivity in Egypt. I mean, many Mayen or Aztec tribes still speak their thong in combination with Spanish and they have been integrated under Spanish domination for 500 years now.
As for Elijah…I don’t know…Hebrew aslo. I think it is possible to state that Hewbrew does not differ that much from Arabian, considering that the Arabs also believe they are decendents of Abraham (Ibrahim). Maybe there was some kind of proto-Middle East Language that was spoken throughout the region at that time. Only the Egyptians would have spoken a distinguished language.
Well, Arabic and Hebrew (as well as Phoenician, Eblaite, Akkadian, Aramaic, Syriac, Amharic, Tigrinya, Maltese, Ge’ez, and others) are what we call
Semitic languages. Hebrew belongs to the Canaanite subfamily of Northwest Semitic. Both the Northwest Semitic languages and the various Arabic languages belong to the Central Semitic group.
It is said that the main distinction between Arabic and the Northwest Semitic languages is the presence of broken plurals in the former. The majority of Arabic masculine non-human nouns form plurals in this manner (called inanimate plural), whereas almost all nouns in the Northwest Semitic languages form their plurals with a suffix. For example, the Arabic بيت
bayt (‘house’) becomes بيوت
buyūt; the Hebrew בית
bayit becomes בתים
battīm.
As for Egyptian, it is actually related (albeit more distantly) to Semitic languages, in that they are both grouped together in the
Afroasiatic (aka Hamito-Semitic) language family.