quot

The root quot begins as a question. Latin quot simply meant "how many?" — the word a Roman would use to ask the size of a crowd, the count of coins, the number of days. Its cousin quotus asked a slightly different question: not "how many?" but "which one in the sequence?" — the how-many-th, as in "on which day?" or "in which chapter?" And a third relative, quantus, asked "how great? how much?" All three grew from the same ancient interrogative root kʷo-, the same root that gives English its wh- question words (who, what, which). So at heart, this family is a family of measuring questions.

From quot/quotus came the most surprising member: quote. In medieval times, scholars copying manuscripts needed to point readers to a specific passage, so they would quotāre a text — literally "mark it with the number" of its chapter or section ("which-numbered" passage). Over time the act of pointing to a numbered passage shifted into the act of repeating that passage's exact words. That is how "to number a chapter" became "to cite someone's words." And then English took one more leap: a merchant asked to state his price was, in effect, citing a figure — so quote came to mean "to state a price," and a quotation is both a cited passage and a stated price. The same word covers your favorite line from a book and the estimate from a plumber.

The other quot words stay closer to counting. Quota is literally "how great a part" — quota pars, the share that falls to each person — so it became a fixed assigned number: an import quota, a sales quota. Quotidian comes from quotus dies, "on the how-many-th day," which settled into "every single day" — and because what happens every day is unremarkable, quotidian also came to mean "ordinary, commonplace." The daily becomes the dull.

Meanwhile the quantus branch gave us pure measurement. Quantity is "how-much-ness," the amount of a thing. Quantum is the neuter form quantum, "how much," originally just "a given amount, a portion" — which is why we still say someone has a quantum of comfort. In 1900 physicists borrowed it for the smallest fixed amount of energy that can exist, and quantum leapt into modern science. A quantum leap is, ironically, a jump of the tiniest possible size — though in everyday English it now means a huge advance.

The pattern across the whole family: start with a question about amount (how many? how much? which in order?), and you arrive at words for counting, sharing, repeating, and measuring the world.