[*] 150. The Relative, Interrogative, and Indefinite Pronouns are originally of the same stem, and most of the forms are the same (compare § 147 with § 148). The stem has two forms in the masculine and neuter, quo-, qui-, and one for the feminine, quā-. The interrogative sense is doubtless the original one. [*] a. Old forms for the genitive and dative singular are quôius , quoi . [*] b. The form quī 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 quīcum, with whom, as an interrogative or an indefinite relative. [*] c. A nominative plural quēs (stem qui-) occurs in early Latin. A dative and ablative plural quīs (stem quo-) is found 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, quōcum, quīcum , quibuscum .
[*] Note.--But occasionally cum precedes: as, “ cum quō ” (Iuv. 4.9) .