INTERROGATIVE PRONOUN

quis quid [who? which? what?]

SG.

M. F. N.
Nom. quis quis quid
Gen. cuius cuius cuius
Dat. cui cui cui
Acc. quem quem quid
Abl. quo quo quo
PL      
Nom. qui quae quae
Gen. quorum quarum quorum
Dat. quibus quibus quibus
Acc. quos quas quae
Abl. quibus quibus quibus


quis librum tibi dedit? [Who gave you the book?]
cuius librum Caecilius tibi dedit? [Whose book did Caecilius give you?]
cui librum Grumio dedit? [To whom did Grumio gave the book?]
quid dedit? [What did he give?]
a quo praemium datum est? [By whom was the reward given?]

Interrogatives are sometimes modified by adding the prefix ec- or the suffix -nam.
ecquis? [is there anyone who?]
quisnam? [who, pray tell?]

quid? (n. acc.) can be used as an adverb to mean 'why?' [for what reason?].
Quid hic nunc stas? [Why are you standing here now?]

RELATIVE PRONOUN

qui quae quod [who, which, that]

SG.

M. F. N.
Nom. qui quae quod
Gen. cuius cuius cuius
Dat. cui cui cui
Acc. quem quam quod
Abl. quo qua quo
PL      
Nom. qui quae quae
Gen. quorum quarum quorum
Dat. quibus quibus quibus
Acc. quos quas quae
Abl. quibus quibus quibus

The gender and number of a relative pronoun are determined by its antecedent, the case, however, by its use in its own clause.
vir qui librum tibi dedit te laudavit. [The man who gave you the book praised you.]
vir cuius librum Caecilius tibi dedit te laudavit. [The man whose book Caecilius gave you prasied you.]
vir cui Caecilius librum dedit te laudavit. [The man to whom Caecilius gave the book praised you.]
femina quam laudas est docta. [The woman whom you are praising is talented.]
homo de quo dicebas est amicus carus. [The man about whom you were speaking is a dear friend.]


INTERROGATIVE ADJECTIVE

qui quae quod [what? which? what sort of?].

Its forms are identical to those of the relative pronoun, except that quis is occasionally substituted as the nominative singular of qui and quae.

qui venti cursum tibi dederunt? [Which winds gave you your course?]
cuius libri fuit Cicero auctor? [Of which gook was Cicero the author?]
cui amico librum dederunt? [To which friend did they give the book?]
quem librum tibi dedit? [Which book did he give you?]
quod praemium dedit? [What reward did he give?]