I've been reading books on Latin to understand its origin. "Long Live Latin" provided some answers (see P 31 below) plus some other interesting things about the language:
P11 Who among Cicero’s contemporaries spoke the way he wrote? Nobody. Not even Cicero himself. What about modern writers such as Virginia Woolf for Henry James? It’s all literature – if we are using a criterion that a language must be spoken or it is dead is not valid, because as written it is art a construction, a calculation, stylized, like music or painting.
P16 The double origin of English vocabulary is obvious in the different roots of semantically related nouns and adjectives: consider the pairs “sun/solar”, “moon/lunar” and “tooth/dental”. The noun is Germanic, the adjective is Latin.
P31 How did Latin itself come to be? … the Roman people of Latium were born from a fusion of Trojan refugees and the local population. The goddess Juno, toward the end of Virgil’s narrative (in the Aeneid XII.823), convinces Jupiter to let the language of Rome, this new city, remain that of its first inhabitants: the “indigenas Latinos”. Latin, therefore, according to the myth, would be a product of the original population, as it indeed proves itself to be through linguistic analysis. At the very beginning, it was the tongue of a small community. With the years and the centuries, and in proportion to the growth in power and prestige of its city, Latin became the language of an enormous empire…
P32 Latin belongs to an extended linguistic family, which boasts some eighty members, among them ancient Greek, Sanskrit, and the Slavic and Germanic languages. Latin had to clear its path in a crush of concurrent languages: Etruscan, Oscan, Umbrian, Faliscan, Messapian, Venetic …
P34 There are six logical functions in all, and therefore six inflections (the grammatical cases): nominative (which marks the subject), genitive (used to express possession), dative (which marks the recipient of an action), accusative (marks the direct object), vocative (used to address someone) and ablative (to express separation or the means by which an action is performed, often preceded by a preposition).
P35 Each word has twelve different inflections, six in the singular, six in the plural. Taken all together, this is known as a word’s declension. Indo-European included two additional cases: the locative and the instrumental.
Old Latin is attested to in hundreds of epigraphs… It is a coarse language, far from anything we might call literature: its orthography varies and its grammar is incoherent.
P86 …Latin, unlike Greek, has a dearth of vocabulary. Lucretius had to invent new terms or extended the meaning of a term. His methods are “semantic saturation” and “metaphorization”.
I'm not giving a star rating as most of the book is for those that can read Latin to appreciate the discussion offered.