a. Old forms for the genitive and dative singular are quoius, quoi.
b. The form quí is used for the ablative of both numbers and all genders; but especially as an adverb (how, by which way, in any way), and in the combination quícum, with whom, as an interrogative or an indefinite relative.
c. A nominative plural qués (stem qui-) is found in early Latin. A dative and ablative quís (stem quo-) is not infrequent, even in classic Latin.
d. The preposition cum is joined enclitically to all forms of the ablative, as with the personal pronouns (§ 143. f): as, quócum, quícum, quibuscum.
NOTE: But occasionally cum precedes: as, cum quó (Iuv. iv. 9).