1. The Dative case

2. The Dative is used for Indirect Objects
Along with the imperative/command, we often see an indirect object (marked i.o.):
Open the door for her
Take the paper to your brother
Give me a break = Give a break to me
Buy your friends a dinner = Buy a dinner for your friends

3. Dative Case/ indirect object
There are many ways to explain and identify the indirect object in English.
In Latin, it is easy:
the indirect object is in the dative case --and should be translated "to" or "for".
The dative has many uses and, strictly speaking, the indirect object is only one. But for now, just translate it as “to” or “for”.

4. How to recognize (or expect) the dative
Datives are generally only used with verbs of giving, showing, or performing a service or disservice to/for someone else.
At this point, datives are usually persons or at least animals.

5. Dative noun (and adjective) endings
Dative case endings:
1st dec. 2nd 3rd
singular -ae -ō -ī
plural -īs -īs -ibus
(there are no separate dative neuter endings)

6. Mark the dative with i.o. for indirect object
V I.O. D.O.
Invenī principi equum!
Find a horse for the leading man! 
V. I.O. D.O.
Dā nuntiīs vaccam!
Give (to) the messengers a cow!
V. I.O. D.O.
Ostende filiae vulnera!
Show (to) the girl the wounds!

7. Verbs and adjectives that take the dative
Some verbs normally take the dative, for what might seem a direct object in English. Crede ancillae! Believe the slave girl! (credo, credere) Parce hostibus! Spare the enemies! (parco, parcere)

8. Adjectives that take the dative
And some adjectives regularly take the dative as well.
propinquus, a, um
Villam ocēanō altō propinquam magī statuērunt.
gratus,a,um
Donum puellae nōn erat gratum.
carus,a,um
Putāvit Marcus Antonius nomen Caesarem esse turbae carum.
sacer, sacra, sacrum
Aram sacram Dianae delevit hostis.

9. The dative can also be used in relative clauses
The dative can also be used in relative clauses. The forms are simple, cuī in the singular and quibus in the plural
Singular masculine feminine neuter
nominative quī quae quod
dative cuī cuī cuī
accusative quem quam quod
ablative quō quā quō
Plural
nominative quī quae quae
ablative quibus quibus quibus
accusative quōs quās quae

10. Dative relative clauses
videt puellam cui saccos iactaverat latro.
hostes deos quibus templum erat sacrum timebant.

11. Interrogative dative pronouns
The same forms are used to ask questions.
Cui praemium dux dedit?
Quibus imperator pepercit?