Case Name
and Typical Meaning / Use

Sing./Plural
Endings

Examples

Nominative

The "subject case": the subject is the word found by asking WHO or WHAT before the verb.

-Û

-UA

cornû, cornua

Dextrum cornû legionem fugaverat.
  The right flank had routed the legion.
 
Cornua sunt animalium ornamenta. 
  Horns are features of animals.
 

Genitive

The "possession case": The genitive word corresponds to the word that takes an apostrophe in English. If (A) is in the genitive, (A) possesses something else (B), with the emphasis falling on (B), so that (A) is somewhat like a modifier of (B): in student's book (= discipuli liber), the possession-word qualifies the meaning of the noun book. 

-ÛS

-UUM

cornûs, cornuum

Dextrî cornûs cohortês sunt secûtae.
 The cohorts of the right flank followed.
 
Amplitûdô cornuummultum â nostrôrum boum cornibus differt.
 The size of the horns is very different from the horns of our cattle.

Dative

The "indirect object case": the indirect object is found by asking TO / FOR WHOM? or TO / FOR WHAT? after the verb. Certain verbs govern the dative.

-Û

-IBUS

cornû, cornibus

Sinistrô cornû Antonium praposuerat.
  He had put Antonius in charge of the left flank.
 
Arida sarmenta boum cornibus alligavit.
  He tied dry twigs to the horns of the cattle.
 

Accusative

The "direct object case": the direct object is usually found by asking WHO or WHAT after an action-verb whose action has a receiver. "We hold these truths." The accusative is also used after certain prepositions.

-Û

-UA

cornû,  cornua

Dextrum Caesaris cornû adgrediêbantur.
  They were attacking Caesar's right flank.
 
Illud animal cornua habet.
  That animal has horns.
 

Ablative

The "by-with-from case": Certain prepositions and certain verbs govern objects in this case. Used alone it can have an adverbial meaning, for example, to indicate by what means something is done.

-Û

-IBUS

cornû, cornibus

In fidibus testûdine resonâtur aut cornû.
  By means of a shell or horn, a sound is echoed back on strings.
 
Hoc animal cornibus armâtum est.
  This animal is armed with horns.