What are two tests for an adjective?

Two tests for an adjective are the substitution test and the modification test. The substitution test involves replacing a Word in a sentence with an adjective to see if it retains the same meaning, while the modification test checks if a Word can modify a noun, providing more information about it. For example, in the phrase "the tall building," "tall" is an adjective because it modifies the noun "building." If you can ask questions like "Which one?" or "What kind?" about the Word, it's likely an adjective.