The mantra of most first year Latin students learning how to properly use adjectives in a sentence. In the Latin language, adjectives must agree with the noun which they are describing in case, number, and gender, so as not to confuse the noun which the adjective is describing with another one ("The greasy boy ate the hungry chicken"). It is common syntax in Latin for one object to require an agreement in case, number, and gender, with something else (ie: relative pronouns also must agree in such a manner).