For most of her life, my grandmother was a teacher in a one-room schoolhouse in rural Tennessee. In old age, unwilling to shake off the discipline of decades, she would instruct me in all sorts of subjects – from threading a bobbin to Caesar’s Latin – that she believed would prove useful to me later. I must have been 8 or so when she first intoned to me, “Gallia est omnis divisa in partes tres,” and then, after a significant pause, translated, “All Gaul is divided into three parts.” She also dropped pregnant hints about a mysterious construction, to which she was unusually partial, called the “ablative absolute.” This meant little to me, though I was struck by the compression of her examples (such as “armis obsidisque acceptis,” “arms and hostages having been received”), even if I couldn’t figure out how to employ this arcane knowledge in everyday speech.

Echoes of these early teachings must have lingered. When I came to study Latin in high school, some lessons had a familiar feel though – vae victis! – I wasn’t very good at them. What impressed me (and still impresses me) was how greatly Latin drills, along with the struggle to decipher a Latin sentence with its baffling word order, widened and deepened my understanding of English. Latin provided a grammatical model thanks to which certain constructions in my own language became suddenly clear.

The difference between “he” and “him,” for example, could be understood as the switch between subject and object, covered in Latin by the accusative case (a puzzling term at first sight). Later, when I studied other languages, the early influence of Latin categories proved helpful, even when the model had to be stretched and bent to accommodate them. I still think this one of the best reasons for studying Latin or Greek as a child: Both languages, with their intricately elaborated grammatical analysis, hold out the possibility of a logical grasp of what initially seems a sheer farrago of alien forms and patterns.

I’m no Latinist, though I can still follow Virgil or puzzle out a Horatian ode, but the language remains endlessly alluring to me. I daydream of taking it up again, this time seriously, if I ever retire, and I’m sure many others harbor similar distant projects. What is it, I wonder, about this supposedly dead tongue that explains its enduring hold?

For a possible answer, “A Natural History of Latin: The Story of the World’s Most Successful Language” (Oxford University Press, 305 pages, $24), by Tore Janson, provides a superb place to start. Mr. Janson is an emeritus professor of Latin at Goteborg University, Sweden, and as you might expect he knows everything there is to know about Latin in its long history and in its various, rather fabulous, permutations. Even better, the translation by Merethe Damsgard Sorensen and Nigel Vincent not only reads beautifully but has been adapted for English readers, so that the examples and illustrations used throughout have immediate pertinence.

Unlike Gaul, Mr. Janson’s history is divided into five sections. Each contains a brief and sometimes witty essay on some aspect of Latin, ranging from “How Latin Became Latin” to “How Bad Were the Romans?” and clear disquisitions on such matters as the calendar, Roman law, Cicero, and Quintilian on rhetoric, and the everyday palaver of ordinary Romans. He devotes a section to the spread and transformation of Latin throughout Europe, discussing everyone from Heloise and Abelard to Linnaeus, as well as the impact of Latin on English, French, and German.

Mr. Janson’s 20-page precis of Latin grammar is the best and most compact account I’ve seen (at last, thanks to Mr. Janson, I understand that wretched ablative!). The final parts of his book contain a basic vocabulary and a list of “common phrases and expressions,” eminently useful for all occasions, from a papal coronation to a cocktail party. For ticklish situations I’m especially fond of St. Augustine’s line, “Da mihi castitatem et continentiam, sed noli modo” (“Give me chastity and restraint, but not just now”).

If you’re wondering how bad the Romans were, Mr. Janson gives a scrupulously fair account. He praises Roman virtues – their love of the “simple life,” their courage and respect for justice – but he also notes their harshness. Thus the consul Torquatus had his own son executed, despite his bravery in battle, for disobeying an order. Mr. Janson remarks of this, “Personally, it makes me feel sick,” and goes on to link such severity with later enormities in Fascist Italy. He does this not out of some anachronistic impulse but to show that an ideal, such as that of total obedience, displays a disturbing Janus face.

Latin is eminently quotable, and this history swarms with memorable statements. All, even those uttered off the cuff, have that eerie marmoreal quality of sentiments incised in stone. The native pithiness of Latin contributes to this effect, as does its startling word order; English is bluntly linear, whereas Latin, with its case endings, often displays a side-stepping, almost hopscotch effect but one under intense compression. When Tacitus writes of war, “Ubi solitudinem faciunt, pacem appellant” (“Wherever they create a desolation, they call it peace”), we are left in a certain suspense before the final verb, with its sardonic sting. The symmetry in the placement of the two nouns and their outriding verbs can’t be replicated in English, but this gives the sentence its caustic poise.

When I hear Latin described as “dead” I take it “cum grano salis.” Not only because it is still spoken and written in such ancient precincts as the Vatican, where just last week we heard proclaimed “urbi et orbi” the much-anticipated sentence “Habemus papam” (“we have a pope”); nor because eccentric professional Latinists in Europe and North America still infuse the Ciceronian and Virgilian lexicon with neologisms drawn from all areas of modern life, from computerese to pop culture; nor even because Latin still forms the bedrock of all our vernaculars. It lives on and continues to fascinate because it is the ideal medium for that strange process by which the most fleeting of our activities – our utterances – take on some tremulous semblance of perpetuity.