I need you to return those books I lent you last month. (Identify the word class of the underlined word 'those')

In this sentence, 'those' specifies which books are being referred to—it points out specific books. Words like 'this', 'that', 'these', and 'those' that come before nouns to identify them are called demonstrative determiners. In modern grammar, these are classified as determiners rather than adjectives, as they help determine the reference of the noun. Therefore, 'those' is a determiner.