Is there a root language for Hebrew and Arabic? Historical Linguistics is about Finding Patterns.

Is there a root language for Hebrew and Arabic?

"Yes.

"There is no written record of such a language, but we know that one existed.
To answer why we know this, I need to be a bit irrelevant for a moment.

"Grimm’s Fairy Tales is one of the most famous books of all time.
The stories in it were collected from around what would soon become Germany
by the Brothers Grimm, Jacob and Wilhelm. As such, it was originally published in German
- in fact, it’s the single most famous and most-read work of German literature
- but it’s since been translated into over 160 different languages and dialects.
It has been called one of the founding works of Western culture.

Kinder- und Hausmärchen.

"That’s probably what you think of when you hear of Jacob Grimm.
What you probably don’t know about him is that he was a pioneer in linguistics,
language families, and sound changes and is famous in historical linguistics
as the creator of Grimm’s law.

"First, a bit of backstory. People in Europe had always noticed
similarities between languages but had assumed them
to be a result of thousands of years of borrowing.
To a degree, that was true, but there was more to it than was thought.

"By the end of his life, Sir William Jones knew 42 languages to various degrees
and was an accomplished lawyer. He also accidentally invented linguistics.

"Jones arrived in British India in 1783 to be a lawyer and quickly fell in love
with the local culture, founding the Asiatic Society a year later.
Sanskrit was the Indian equivalent to Latin (which he also spoke), so he had to learn it.

"In learning it, he discovered something interesting:
Sanskrit was oddly similar to Classical Latin and Ancient Greek.
In 1786, he wrote a passage that is considered to be what founded linguistics:

"The Sanscrit language, whatever be its antiquity, is of a wonderful structure;

"more perfect than the Greek, more copious than the Latin,
and more exquisitely refined than either, yet bearing to both of them a stronger affinity,
both in the roots of verbs and the forms of grammar,
than could possibly have been produced by accident;

"so strong indeed,
that no philologer could examine them all three, without believing them
to have sprung from some common source, which, perhaps, no longer exists;

"there is a similar reason, though not quite so forcible, for supposing
that both the Gothic and the Celtic, though blended with a very different idiom,
had the same origin with the Sanscrit; and the old Persian
might be added to the same family."

"Remarkably, he was correct in every one of those: today, Sanskrit, Greek,
Latin, Gothic, Celtic, and Persian - along with English, French, Russian,
and related languages - are part of the Indo-European language family.

"However the language change was still considered to be random,
and there wasn’t a real scientific way to determine what was related to what.
At least, not yet.

"Now back to the Grimms: During and after the Napoleonic wars,
a new kind of German nationalism bubbled up, united by a common language.
This would lead to three things important here: the creation of Germany,
the collecting of Grimm’s Fairy Tales, and a linguistic revolution.

"The Brothers Grimm did two things to contribute to this: the first,
and most influential, was that they went around and collected German folk tales,
myths, and legends. (To make something clear here: the Grimms didn’t write the stories,
they just collected them.)

"While Jacob did help with story-collecting, that job went mostly to Wilhelm.
Jacob spent his time doing something else:
he looked through lots of dictionaries in lots of languages.

"This is something he might find:

"German: Vater (said “fater”), English: father, Dutch: vader (said “fader”), Swedish: fader,
Latin: pater, Greek: pateras, Spanish: padre, Italian: padre, Albanian: baba,
Bulgarian: bashta, Ukrainian: bat’ko.

"Notice a pattern? The words for “father”
almost all start with a P or B (which are very similar sounds)
- even English has “papa”!

"There are, however, four languages whose words start with an F.
Interestingly, they all just happen to be spoken in northern and northwestern Europe.

"Look at another example here:

"German: Fuß, English: foot, Dutch: voet, Danish: fod, Swedish: fot,
Ancient Greek: poús, podós, Latin: pēs, pedis, Sanskrit: pāda,
Russian: pod ("under; floor"), Lithuanian: pėda, Latvian pēda.

"Again, all the words for “foot” start with P except for English,
German, Dutch, and the Scandinavian languages.

"Here’s another one:

"German: Hund, English: hound, Dutch: hond, Swedish: hund, Ancient Greek: kýōn,
Latin: canis, Welsh: ci (pl. cwn), Albanian: qen.

"Starting to notice a pattern? Grimm did. He found that where other European
- and some Indian - languages had a “p” sound,
the very specific group of languages had an “f” sound.
Same with “k” and “h”, respectively.

"This led him to create Grimm’s law: certain sounds in other European languages
would turn into other sounds in a certain language group:

bʰ > b > p > ɸ; dʰ > d > t > θ; gʰ > g > k > x; gʷʰ > gʷ > kʷ > xʷ.

"Or in a simpler way of writing it,

bh > b > p > f; dh > d > t > th; gh > g > k > kh; gwh > gw > kw > khw.

"Since this is a sound-change pattern that can be seen repeatedly in said language group,
it’s fairly easy to see that they’re related. This group has a name now:
it’s called the Germanic languages, and it includes German (of course),
English, Dutch, Frisian, Low Saxon, Yiddish, Afrikaans, Scots, Swedish,
Danish, Norwegian, Elfdalian, Faroese, and Icelandic.

"We can also see that the sound changes all relate to words in other languages,
so we can say with a good degree of certainty that the Germanic languages
are related to most other European languages.

"Due to other sound change patterns found in Sanskrit (eg. Latin pater, Sanskrit pitar),
we found out that most of the major languages in India
are related to most of the major languages in Europe,
and we call the language family Indo-European.

"It includes the Germanic, Italic (languages related to Latin),
Slavic (eg. Russian, Czech, Polish), Baltic (Lithuanian, Latvian),
Celtic (eg. Irish, Welsh), Indic (eg. Hindi, Marathi), Iranian (eg. Pashto, Persian),
Hellenic (Greek), Albanian, Hittite, and Armenian sub-families.

"By reverse-engineering the sound changes, we’re able to reconstruct Indo-European,
despite having absolutely no written record of what it was like.

"This language is known as Proto-Indo-European, or PIE.
(Linguists have heard every possible pun, so don’t even try.)

"Arabic and Hebrew are not related to any Indo-European language.

'We know this because they have no word-change patterns
that relate to any IE language.

"But they do have patterns that show that they relate to one another,
as well as to Akkadian, Amharic, and Aramaic.

"Their patterns also show that they’re related to other African languages,
such as Hausa and Somali, though not as closely.

"From this, we can not only deduce a family tree for this group of languages
- called Afro-Asiatic - but also reconstruct a language
we have zero physical evidence for, Proto-Afroasiatic.

"Cool, eh?

"Adapted from my answer here."