"last year" 是一个英语短语，由冠词 "last" 和名词 "year" 组成。它用来指代紧接在当前年份之前的年份。例如，如果当前年份是2022年，那么"last year" 就指的是2021年。

"last year" is a determiner phrase that consists of the determiner "last" and the noun "year". It is used to refer to the year that came immediately before the current year. For example, if the current year is 2022, "last year" would refer to 2021.