art. (用于可数名词或单数名词前,表示未曾提到的)一(人、事、物); 用于前有形容词或后有短语的不可数名词前; 任何一; 每一
Oxford 3000 / Collins.5 / BNC.5 / COCA.5
indefinite article
A or an is the indefinite article. It is used at the beginning of noun groups which refer to only one person or thing. The form an is used in front of words that begin with vowel sounds.
a 或 an 为不定冠词,用于表示单个事物或人的名词词组之前。an 用于以元音开始的单词之前。
a (an) indef. art. 一个
〔辨析〕通常用于单数可数名词之前,泛指某类人或事物中的一个。
one num. 一,一个
〔辨析〕强调数量的概念,说明是一个而不是两个或三个。
n.
from A to B
from A to Z