a determiner (NOT PARTICULAR)
A1 used before a noun to refer to a single thing or person that has not been mentioned before, especially when you are not referring to a particular thing or person
一(个)(用于名词前,表示未曾提及的,尤其是非特指或不想让对方确切知道的事物或人)› used before some uncountable nouns when you want to limit their meaning in some way, such as when describing them more completely or referring to one example of them
(用于一些不可数名词前,在某种意义上起限定性作用)A2 used before some nouns of action when referring to one example of the action
(用于某些行为名词前)一下,一次A2 used when referring to a unit or container of something, especially something you eat or drink
(尤指饮食的)一份,一客A2 used before the first but not the second of two nouns that are referred to as one unit
(用于被视为一体的两个名词中的第一个词前)一副,一套,一组A2 used before some words that express a number or amount
(用于某些表示数量的词前)› used in front of a person's name when referring to someone who you do not know
(用于不认识的人名前)有个,某一(个)› used in front of someone's family name when they are a member of that family
(用于某人的姓之前,表示其为该姓家族成员)