多少

多少 (duōshao) is 多 (many) fused to 少 (few), and the fusion is systematic. Chinese regularly names a dimension by welding its two poles: 大小 (big-small) is size, 长短 (long-short) is length, 轻重 (light-heavy) is weight, 快慢 (fast-slow) is speed, 远近 (far-near) is distance, and 高矮 (tall-short) is stature. The logic runs: the pair of opposites defines a scale, and the compound names the scale itself. As a question word, 多少 asks where on the quantity scale the answer falls. The most famous member of the family has drifted furthest: 东西 (dōngxi, east-west) became the everyday word for "thing," the stuff one shops for in both directions of the market street.

The two characters are old pictographic arguments. 多 stacks two 夕 (moon/evening) forms: night after night, an accumulation. 少 is 小 (small) with a stroke shaved away: less than little. Their fusion is attested in classical texts, including the openings every learner eventually meets: Meng Haoran's dawn poem 春晓 ends 花落知多少, "who knows how many blossoms fell," using 多少 exactly as the modern language does, thirteen centuries ago.

The choice between 几 and 多少 quietly tells the listener what scale of answer you expect, so using the wrong one is grammatical but socially odd: asking a metropolis 你们城市有几个人 sounds like you expect to count its residents on your fingers. 几 also moonlights outside questions. Before a measure word in a statement it means "a few" (说几句话, say a few words), and stacked after a round number it means "and some": 二十几岁 is twentysomething, 一百几十块 is a hundred-odd yuan. The date-and-time questions split the labor: 几月几号 asks the date, 星期几 asks the day of the week, and 几点 asks the hour, all small-range and therefore all 几.

多少 has one statement idiom worth owning early: reduplicated 多多少少, "more or less, to some degree" (他多多少少有点后悔, he somewhat regrets it). And in classical flavor 多少 can exclaim rather than ask, as in 花落知多少: not a request for a count but a sigh at uncountability, the same rhetorical slide English makes with "how many dreams were lost."

多 alone, prefixed to an adjective, builds the "how X" questions: 多大 (how old / how big), 多高 (how tall), 多远 (how far), 多长 (how long), 多重 (how heavy). Asking an adult's age is 你多大了, softened for elders into the honorific 您多大年纪. The answers recycle the adjective or drop it entirely for bare numbers: 我一米七五 (I'm 1.75 meters), 三十岁 (thirty years old). The pattern always picks the scale's larger pole, 大 not 小, 高 not 矮, 远 not 近: the unmarked direction of every dimension in Chinese, as in most languages, is up.