1. Adjectives agree with their nouns in Gender, Number, and Case:
vir fortis [a brave man]
multus sanguis [much blood]
urbium magnarum [of great cities]
cenam optimam [the best supper]


2. To agree with two or more nouns the adjective becomes plural or follows the nearest noun:
Caecilius et Grumio laeti sunt. [Caecilius and Grumio are happy.]
Servus totam et culinam et atrium lavat. [The servant washes the whole kitchen and hall.]
Natura inimica sunt libera civitas et rex. [By nature a free state and a king are hostile.]
multae operae ac laboris [of much trouble and toil]
vita moresque mei [my life and character]


3. A collective noun may take an adjective of the gender and number of the individuals implied:
Multitudo convicti sunt. [A multitude were convicted.]
Magna pars raptae. [A large part of the women were seized.]


4. Abstract nouns may have an Adjective in the neuter plural:
Stultitia et iniustitia ... sunt fugienda. [Folly and injustice... are [things] to be shunned.]
Labor (m.) voluptasque (f.) societate naturali sunt iuncta (n.). [Labor and delight are bound by natural alliance.]


5. Adjectives as nouns:
masculine = people in general,
feminine = women,
neuter = things.
meus propinquus [my neighour]
honestum [an honorable act, or virtue (as a quality)]
Omnes fortia laudant. [All men praise bravery (brave things).]
Varium et mutabile semper femina. [Woman is ever a changing and fickle thing.]
Malum mihi videtur esse mors. [Death seems to me to be an evil.]


6. Adjectives as nouns:

with added meaning from constant association
africus [ventus] [the southwest wind]
Ianuarius [mensis] [January]
vitulina [caro] [veal (calf's flesh)]
fera [bestia] [a wild beast]
patria [terra] [the fatherland]
Gallia [terra] [Gaul (the land of the Galli)]
hiberna [castra] [winter quarters]
triremis [navis] [a three-banked galley, trireme]
argentarius [faber] [a silversmith]
regia [domus] [the palace]