一 + Measure Word + Noun
一 (yī) means "one" and is the most basic numeral in Chinese. When placed before a measure word and noun, it specifies a single item or introduces an unspecified member of a category, similar to the English indefinite article "a."
桌子上有一杯咖啡。
zhuōzi shàng yǒu yì bēi kāfēi.
There is a cup of coffee on the table.
我想买一本小说看看。
wǒ xiǎng mǎi yì běn xiǎoshuō kànkan.
I want to buy a novel to read.
她养了一只很可爱的猫。
tā yǎng le yì zhī hěn kě'ài de māo.
She has a very cute cat.