“一”在成语中变化很大,用法也很多。从词性来分,主要有这么几类:(一):用作数词(1)作定语,直接修饰名词,如“一发千钧”、“一国三公”。(2)作状语,直接修饰动词,如“一鼓作气”、“一劳永逸”。(3)虽是数词,但不表示数量,主要表示“小、少”的意思,如“一知半解”、“沧海一粟”。 “I” has changed a lot in idioms, and there are many usages. From the part of speech, there are mainly several categories: (a): as a word (1) as an attributive, directly modifies nouns, such as “one generation and three states”. (2) As adverbial modifiers, directly modify verbs, such as “doing one thing at a time,” and “do it once and for all.” (3) Although it is a numeral, it does not mean quantity. It mainly means “small, little” meaning “a little knowledge” and “a drop in the sea.”