which's

English

Etymology 1

From which +‎ -'s (possessive clitic).

Pronoun

which's

(colloquial, nonstandard, proscribed) Of which; alternative to inanimate sense of “whose”.
- 2001, Jane Goodall, Beyond Innocence: An Autobiography in Letters : the Later Years, page 116:
  Do you happen to know if - gosh, I've forgotten his name - from the zoo film unit is still operating at that little film studio which's name I've also forgot?
Of or pertaining to [some noun phrase ending with] which.
- 1899, Minisink Valley Historical Society, Collections, Connecticut Historical Society, page 86:
  Whereas we are informed that the small pox prevails at New York, Connecticut, &c, the preventing of which’s coming into this place is of the utmost consequence, all persons are hereby notified that orders are given by us for all vessells coming into this port to hoist a jack at the main topmast head, […]
- 1992, Jack Rabin, Handbook of Public Budgeting, CRC Press, page 476:
  The yield is comparable to the best corporate securities, each of which’s principal is relatively safe.
- 2004, Mark Axelrod, Borges' Travel, Hemingway's Garage: Secret Histories, page 74:
  The discovery of the Indianapolis Times was serendipitous since his two favorite teams were the Indiana Hoosiers and the Indianapolis Colts, the latter of which’s move from Baltimore prompted Poe’s lugubrious novel The Fall of the House of Irsay.

Usage notes

In the inanimate “of which” sense, which's arises out of doubt about whether whose can be used with an inanimate antecedent. In standard English, whose is the possessive of form of both who and which, so whose is appropriate for such antecedents.

In the noun-phrase-final sense, which's is best analyzed not as a single word, but as the last word of a noun phrase, the whole phrase to which -'s is appended. In this sense, changing which's to whose is hypercorrection.

Synonyms

(whose): of which, whose

Etymology 2

From which + is.

Contraction

which 's

(nonstandard) contraction of which is
I didn’t ask for installation but they still charge me the installation which’s fine for me.
- 1873, William Henry Thomes, The Bushrangers, page 38:
  “Which’s the best man?” continued the young lady with the dark blue eyes.
- 1922, Marion Ames Taggart, Who is Sylvia?, Page & Company Doubleday, Country Life Press, page 267:
  He’s the one that gits the full good ’f a clock, which’s the comp’ny they are.
- 1996, Nelson C. Nye, The White Chip, →ISBN, page 140:
  To the best of my knowledge... which’s not a great deal... the Peraltas weren't here until late in the ’thirties.