It is a view commonly alluded to by amateur linguists, among whom I count myself, that Modern Hebrew is a constructed language “invented” by Eliezer Ben-Yehuda. The official Tumblr of the Language Construction Society once alluded to this, sparking a discussion on the LCS list which introduced a number of equally ridiculous claims, such as that Modern Hebrew was a “reconstructed language” in the same sense as Proto-Indo-European. I have edited my own remarks and am presenting them here, along with other revelations I subsequently came to.
Ben-Yehuda did not need to reconstruct or invent the grammar of Modern Hebrew, which was instead based on the grammar of the Mishnah and of late Biblical Hebrew (see Kohelet for example). All of the changes between what many people incorrectly regard as “true Hebrew” (older Hebrew) and Mishnaic Hebrew were caused by the influence of Middle Aramaic, where possessive pronouns and the construct state are used less frequently, present participles are used to form the present tense (using suffixed pronouns in Aramaic), and the old proto-Semitic imperfect is used as a future tense.
Ben Yehuda’s own role in the revival of Hebrew has also been questioned. There were already efforts underway to revive Hebrew as a spoken language long before Ben Yehuda ever emmigrated to Palestine, and his efforts within his own family were not only unsuccessful but even abusive and damaging. The most credit Ben-Yehuda can be given is that he invented a large number of words, which he placed into dictionaries that were widely popular, and a great many of his neologisms were adopted, both in print and during the first mass-scale revival, the one that made Hebrew effectively the language of Zionism, in the 1920s. Though secular Jews were behind this large-scale revival, they had yeshiva backgrounds; they were well-educated in Jewish tradition in ways that most Jews today are not.
One reason why the revival of Hebrew was so successful is that a large (though almost exclusively male) portion of world Jewry already knew how to read, write, and otherwise communicate in the language; the difficulty came with using it to describe non-religious matters of everyday life. Religious education for men at the time was much more rigorous and much more universal than it is among Jews today, and in many cases (particularly in Eastern Europe), it was the only education available. A man who could not reason in Hebrew was considered a bit of a failure; a man who could also reason in Aramaic was a sage, a rov (see Dovid Katz’s “Words on Fire” for more discussion of this). If you listen to the lectures on dafyomi.org, you’ll get a sense for how Jewish Yeshiva education involves a non-trivial amount of reasoning directly in Hebrew and Aramaic. This type of education is, incidentally, the main source of the various divergent Jewish languages and dialects full of Hebrew and Aramaic terms.
Since its revival, the main grammatical changes that have been made from Mishnaic Hebrew to Modern Revival involve derivational suffixes, largely loans from European languages. There have also been a large number of idioms borrowed from European languages that would certainly be unfamiliar to anyone who understood Rabbinic Hebrew or Mishnaic Hebrew prior to the revival. But this did not involve construction, reconstruction, or anything of the sort; it involved the rather more boring element of semantic borrowing.
Another frequent point raised regards the use of suffixed forms of של instead of the construct form that was typical of the earliest Biblical Hebrew. But this was, in fact, a widespread Canaanite feature, found also in Punic; indeed, it is found throughout Plautus’s Poenulus as “silli” (my), “sillo” (his), and is attested in inscriptions as well. The Phoenician two-word equivalent, ʾš ly, (“my” or literally “which is to me”), shows the ultimate derivation of the Punic and Hebrew pronoun.
The shel pronouns are attested Biblically in Song of Songs 1:6:
אֶת־הַכְּרָמִ֔ים כַּרְמִ֥י שֶׁלִּ֖י לֹ֥א נָטָֽרְתִּי
“my own vineyard I did not keep”
It also appears, for example, in Pirkei Avot, one of the oldest sections of the Mishnah:
אַרְבַּע מִדּוֹת בָּאָדָם. הָאוֹמֵר שֶׁלִּי שֶׁלִּי וְשֶׁלְּךָ שֶׁלָּךְ, זוֹ מִדָּה בֵינוֹנִית. וְיֵשׁ אוֹמְרִים, זוֹ מִדַּת סְדוֹם. שֶׁלִּי שֶׁלְּךָ וְשֶׁלְּךָ שֶׁלִּי, עַם הָאָרֶץ. שֶׁלִּי שֶׁלְּךָ וְשֶׁלְּךָ שֶׁלָּךְ, חָסִיד. שֶׁלִּי שֶׁלִּי וְשֶׁלְּךָ שֶׁלִּי, רָשָׁע:
Pirkei Avot 5:10: There are four types of character in human beings: One that says: “mine is mine, and yours is yours”: this is a commonplace type; and some say this is a sodom-type of character. [One that says:] “mine is yours and yours is mine”: is an unlearned person (am haaretz); [One that says:] “mine is yours and yours is yours” is a pious person. [One that says:] “mine is mine, and yours is mine” is a wicked person.
It is true that the suffixed pronoun and construct state are used less often than של in Modern Hebrew. This is another case where Hebrew was influenced by Middle Aramaic some 2000 years ago, without the need for any language invention or European influence. In Middle Aramaic, you only see the suffixed possessives and construct forms in certain situations, like with kinship terms, body parts, etc. Otherwise, you have an analytic possessive; for example: מִי יֵימַר דִּדְמָא דִּידָךְ סוּמָּק טְפֵי? – “who’s to say that your blood is redder?” There, “your blood” is d’ma didakh.” Or for an example of an analytic construction replacing the construct, “family” is “nasha d’betha” in Modern Aramaic. D’- is used to form the possessive there.
In Modern Hebrew, the suffixed possessive and construct are still productive. The construct gets used to form what we usually call “compound words” rather than possessive constructions. The suffixed possessives get used with new words that fit in the right semantic category, such as יזיז yazíz, “friend with benefits.”
The decision to make Mishnaic Hebrew, rather than an idealized Biblical Hebrew, the standard, was made by Maimonides, when he began composing works in a form that was considered relatively “purified” – contemporary works in the Hebrew of his time tended to be extremely Arabicized. Maimonides made a conscious decision to write in the “purer” Mishnaic Hebrew, and due to his eventual influence, this became the way educated Jews wrote in the coming centuries, including at the time of the revival of Modern Hebrew. This wasn’t a conscious choice made by the revivers of Hebrew; it was the standard that had already existed for centuries. Most people didn’t have any interest in reviving an idealized Biblical Hebrew as fetishized by philologists; they were trying to speak the Hebrew language as it had evolved as the Jewish lingua franca, the one that it was possible to actually begin speaking.
I should add finally that I am not a Zionist and even believe Zionism has done a lot of harm to diaspora communities. I was not taught my own history and culture, was not taught the Ashkenazi pronunciation but was told that Israeli Hebrew was “correct” instead, and was discouraged from learning Yiddish. I had to find out all of this myself, which has taken a great deal of time and painstaking research, something that lots of people seem to be content to avoid while still speaking about the subject with authority.