ADJECTIVES

Adjective Endings (words "hic/ille/ipse" are with pronouns)

1st and 2nd Declension

Case (S)	M	F	N
Nominative	us	a	um
Genitive	i	ae	i
Dative	o	ae	o
Accusative	up	am	um
Ablative	o	a	o
Case (P)	-	-	-
Nominative	i	ae	a
Genitive	orum	arum	orum
Dative	is	is	is
Accusative	os	as	a
Ablative	is	is	is

3rd and 4th Declension

Case (S)	M	F	N
Nominative	is	is	e
Genitive	is	is	is
Dative	i	i	i
Accusative	em	em	e
Ablative	i	i	i
Case (P)	-	-	-
Nominative	es	es	ia
Genitive	ium	ium	ium
Dative	ibus	ibus	ibus
Accusative	es	es	ia
Ablative	ibus	ibus	ibus

Usage:

Put these endings on an adjectives, while matching it to the noun that it modifies in case, number, and gender. Single ending adjectives use only the 3rd/4th declension endings, and only using the Masculine and Feminine endings.

Substantives are adjectives that stand for nouns; these can be masculine, neuter, or feminine.

Possessive Adjectives: Genitive isn't used for possession with these; "Librum tuum lego" -> "I am reading your book"
Common Possessive Adjectives:

In Latina:	In English:
meus, -a, -um	my , my own, mine
tuus, -a, -um	you, your won, yours (S)
suus, -a, -um	his own, her own, yours
noster, -a, -um	our, our own, ours
vester, -a, -um	your, your own, yours (P)
suus, -a, -um	their own

Comparative Adjectives: Are such as "Good, Better, Best..."
Positive: "Gaius est obesus" -> Gaius is fat (obesus, -a, -um)
Comparative (use 3rd): "Messalla est obesior quam Gaius" -> Messalla is fattier than Gaius (obes + (M/F) ior or (N) ius (use base + "ior" (M/F) or "ius" (N) + endings found in the chart below...)
Superlative (use 1st & 2nd): "Titus est obessimus omnium" -> Titus is the fattest of all (obessimus, -a, -um)

Comparative Endings

Case (S)	M	F	N
Nominative	ior	ior	ius
Genitive	is	is	is
Dative	i	i	i
Accusative	em	em	ius
Ablative	e	e	e
Case (P)	-	-	-
Nominative	es	es	a
Genitive	um	um	um
Dative	ibus	ibus	ibus
Accusative	es	es	a
Ablative	ibus	ibus	ibus

1st & 2nd Adjectives (w/ 3 endings): (for –rimus/-limus verbs) – Comparative is "pulchrior"; Superlative is "pulcherrimus"
3rd Adjectives (w/ 2 endings): (for -er verbs) – Positive is "celeriter"; Comparative is "celerior"; Superlative is "celerrimus"
On words such as "elegans, elegantis;" use the 2nd, Genitive part

-LIS ADJECTIVES: (Positive is "facillis, -is, -e"; Comparative is "facilior/ius"; Superlative "facillimus")
The "-lis" Adjectives are: Difficilis; difficult – Similis; similar – Dissimilis; dissimilar – Gracilis; slender – Humilis; humble – Facilis; easy – Fidelis; faithful

Common Irregular Adjectives

Positive	Comparative	Superlative
bonus, -a, -um; good	melior/ius; better	optimus -a -um; best
malus, -a, -um; bad	peior/ius; worse	pessimus, -a, -um; worst
magnus, -a, -um; big	maior/ius; bigger	maximus, -a, -um; biggest
parvus, -a, -um; small	minor, minus; smaller	minimus, -a, -um; smallest
multus, -a, -um; much	plus; more	plurimus, -a, -um; most/very much
multi, -ae, -a; many	plures, plura; more	plurimi, -ae, -a; most/very many

ADVERBS

If an adjective reads "strenuus, -a, -um;" the adverb form would be "strenue"

Positive	Comparative	Superlative
base + "e"	base + "ius"	base + "issime"

As you can see, adverbs are much easier to handle than Adjectives, but there are still irregulars:

Positive	Comparative	Superlative
bene; well	melius; better	optime; best
male; badly	peius; worse	pessime; worst
facile; easily	facilius; more easily	facilleme; most easily
magnopere; greatly	magis; more	maxime; most
paulum; little	minus; less	minime; least
multum; much	plus; more	plurimum; most