uses of cases

Question 1

use of nominative

Answer 1

subject of sentence or clauses

complement eg. this girl is MY SISTER

Question 2

uses of vocative

Answer 2

direct adress

Question 3

uses of accusative

Answer 3

direct object in sentence or clause yet note eg. poor me = me miserum
motion through preposition eg. to italy = Ad Italiam/Romam
time expressions - how long
indirect statement, subject of infinitive
of respect or part affected

Question 4

uses of genitive

Answer 4

possession
partitive eg. more food (more of food)
genitive of quality eg. wise of man (man of wisdom)
after certain verbs and adjectives
causa + gerund/gerundive in genitive (for the purpose of sleeping)

Question 5

uses of dative

Answer 5

indirect object (he gave..to…)
advantage (for…)
after certain verbs and adjectives
possession
agent eg. all the words need to be learnt by us
predicative eg. this book is a source of help to me

Question 6

uses of ablative

Answer 6

with preposition
agent and instrument eg. killed by guard (agent) with sword (instrument)
time - at/when
comparison, ablative without quam
physical description 
price eg. at/for a big price 
after certain verbs/adjectives 
ablative absolute