quot

Quot is indeclinable. One form covers every gender, case and number, so quot homines and quot rerum look exactly alike and the noun beside it does all the grammatical work. It asks "how many" in a direct question, and in an indirect one it takes the subjunctive like any other question word.

Its natural partner is tot, "so many", also indeclinable, and the correlative pair quot ... tot is a fixed pattern: quot homines, tot sententiae is the proverb everyone quotes. Around it sit quotiens, "how often", and quotus, "which in order" - and quotus is the one that does decline, which makes it the one to watch. English quota and quotient come from the family, though not directly from quot itself.