Cows and calves, pigs and sheep are English until we eat them. We’d balk if offered “roast cow” for dinner. Since the 18th century, our meats have demanded French provenance to become palatable. Beef and veal, pork and mutton — deriving from boeuf, veau, porc, and mouton — undergo linguistic marination well before reaching the dining table. The split in usage is historic, dating from the Norman Conquest. Then, as Sir Walter Scott noted, the Anglo-Saxon raised the food while the Norman Frenchman ate it. This is surely exaggerated but the distinction retains its force. A ragout of pork is one thing, pig stew quite another.

This isn’t just squeamishness. It reflects the remarkable voracity of the English language which over the centuries has wolfed down words, idioms, and grammatical structures from conquerors and conquered alike: Latin from the Roman legions, Old Norse from the Viking invaders, French from the Normans entered English ear ly and swelled our word-hoard Later, under the British Empire thousands of exotic terms, from curry to mango to pyjamas, be came so domesticated as to seem indigenous.

This omnivorous linguistic ap petite forms one of the principal themes of Seth Lerer’s wonderful “Inventing English: A Portable History of the Language” (Columbia University Press, 305 pages, $24.95), and yet, it’s far from the whole story. Mr. Lerer deepens his discussion of outside influences on the language with a learned and enthusiastic account of the inner dynamic of English, from the Anglo-Saxon period to the present, so that its amazing richness and uniqueness shine through, century by century.

Mr. Lerer (as his name suggests) is a teacher as well as a scholar; his recorded course on the history of English for the Teaching Company is justly popular. As a writer he’s erudite without ever becoming dull. He knows how to present the driest topics — the dread “Great Vowel Shift” is one of these — in jargon-free prose enlivened by striking examples. He provides useful maps of dialects and linguistic variations, a good glossary and bibliography; and yet, it’s his prose, characterized by a lucid exuberance and a passionate love of his subject, which carries the book all the way from Caedmon and Beowulf to Cab Calloway, Don DeLillo, and the tortured niceties of email English.

Old English was an inflected language with well-defined declensions, comparable to Latin or German, but it also possessed a capacity for word-building; the famous kennings — “swan-road” for the ocean, “walking weaver” for spider — illustrate this vividly. In the earliest surviving English poem, Caedmon’s “Hymn,” composed around 680 C.E., we read that God “first shaped for earth’s children / heaven as a roof.” Strange as that last phrase looks in Old English — “heben til hrofe” (“heaven to roof”) — we can just glimpse the beginnings of our robust English words with their emphatic stresses. As Mr. Lerer traces the alterations in this archaic tongue over half a millennium, we witness its transformation, under the pressure of Latin and Norman French, into something as familiar as it is still strange.

Through close reading of poems and chronicles, Mr. Lerer shows how the native genius of English became ever more flexible. He’s especially good at explaining the decisive impetus that such geniuses as Chaucer, Julian of Norwich, and, ultimately, Shakespeare gave to the language. But unlike other philologists, Mr. Lerer supplies the historical context. He discusses “The Domesday Book” not simply as a linguistic document but as the fiercely acquisitive effort by William the Conqueror to number every acre of English soil; it was the meticulous inventory of his plunder. English grew not only through interchanges with other tongues but out of the calamities of the time; war, disenfranchisement and even torture brought new and terrible words into the lexicon.

Mr. Lerer’s narrative suggests that there’s an inbuilt playfulness to English. The Elizabethans exploited this fully. For them, and especially for Shakespeare, any part of speech could serve as any other. Shakespeare speaks of “a seldom pleasure” or says, “They askance their eyes,” using adverbs as an adjective and as a verb. We do this still, turning names, and even numbers, into verbs (as in “to Google” or “to 86 an order”). And we invent compounds with all the dexterity of Anglo-Saxon word-weavers, as when we speak of “rubber-necking delays.” This grammatical suppleness, constrained only by word order rather than inflection, seems native to our tongue and helps account for its worldwide appeal.

No phenomenon of spoken English is too slight for Mr. Lerer’s inquisitive attention. He notes, for example, that Isaac Newton was fascinated by phonetics — he was part of the 16th-century “Orthoepist” movement, which sought to standardize English — and described sounds made deep in the throat as a “jarring of the throte as when wee force up flegme.” Or he cites William Labov’s finding that “the floorwalkers at Saks Fifth Avenue pronounced the r’s in ‘fourth floor’ more than those at Macy’s, and the least amount of r was heard at S. Klein’s” — an observation I mean to test the next time I go shopping. His discussion of Black English, with its indebtedness to Gullah — the Creole dialect spoken on the South Carolina islands — or its use of verbal aspect (“I be tired”), rather than conventional tense, is astute and sensitive.

A language only lives and grows in the mouths of its speakers, and yet English emerges from Mr. Lerer’s history as a complex personage in its own right, a creature of moods and quirks and rather rumbustious tendencies. Language, and especially English, possesses an inbuilt momentum of invention. We use it but it speaks through us too; by inventing it we invent ourselves as well.

eormsby@nysun.com