Adjective

An adjective is a part of speech that modifies a noun or pronoun, adding detail about which one, what kind, how many, or whose. In "the ancient oak," ancient describes the noun oak. Adjectives usually sit directly before the noun they modify, but they can also follow a linking verb: "The oak is ancient."

Adjectives change form to make comparisons. The comparative (-er or "more") compares two things — "faster," "more careful" — while the superlative (-est or "most") singles one out of three or more — "fastest," "most careful." Standard usage never doubles the markers: "more faster" is always wrong. Articles (a, an, the), demonstratives (this, that), and numbers also function adjectivally by limiting the noun they precede.

Punctuating stacked adjectives is a frequent test point. Coordinate adjectives — ones that independently modify the noun and could be joined by "and" — take a comma between them ("a long, tedious meeting"). Cumulative adjectives build on each other in a fixed order and take no comma ("a small brick house"). If you can swap the adjectives or insert "and" naturally, use the comma; if not, leave it out.

Adjectives appear throughout standardized tests. The ACT English section tests comma use with stacked adjectives and adjective-versus-adverb choices, the Praxis Core Writing exam tests adjectives within parts of speech, and GRE vocabulary leans heavily on adjective-form words. Knowing how adjectives function — and how they differ from adverbs, which modify verbs, adjectives, and other adverbs — pays off across all of them.