What is a fixed adjective?

A fixed adjective is an adjective that does not change form based on the noun it modifies, regardless of factors like number or gender. Unlike some languages where adjectives agree with nouns, fixed adjectives maintain the same form. For example, in English, the adjective "blue" remains "blue" whether describing a blue car or blue cars. This contrasts with languages like Spanish, where adjectives can change to match the noun they describe.