A quantifier is a word or a short phrase that sits with a noun and shows quantity — how much or how many. Much, many, few, little, some, any, no, all, every, and a lot of are typical ones. It does not name the thing; it only tells you the amount of it. You say few friends, much time, a lot of homework. Though actually, grammar books do not all agree on the edges: some call a lot of a quantifier, others call it a phrase, and words like every also feel a bit like determiners. There is a second, specialist use in logic, where a quantifier is a sign meaning 'for all' or 'there is at least one'. That is the same core idea — marking how many — but it is not what most learners meet first.

數量詞。不要和國語課的「量詞」（個、張、條）搞混；英語 quantifier 是 much、few、a lot of 這種表「多少」的詞。