"Whose" is the possessive relative for people AND things in modern English; "of which" or "the [noun] of which" is a formal alternative for things. Both are correct for things, but "whose" is more natural and common.
WHOSE: possessive relative pronoun indicating BELONGING or relationship. Although in Old English it was used only for people, in modern English WHOSE is used for PEOPLE AND THINGS/CONCEPTS. "The company whose shares are listed on the exchange." "The report whose conclusions alarmed the committee." WHOSE introduces a relative clause that modifies the noun that possesses something. STRUCTURE: [antecedent] + WHOSE + [possessed noun] + [rest of clause]. "The employee whose performance has been exceptional." There is no modern restriction to people: WHOSE for things is widely accepted in all formal and colloquial English.
The organization whose governance structure most closely aligns with best practices in the sector is likely to attract institutional investors who prioritize strong oversight.
We are looking to partner with a technology provider whose platform can scale to support a tenfold increase in transaction volume without requiring significant architectural changes.
The restructuring plan, whose implementation will require coordination across six regional offices, has been approved in principle by the executive committee pending final board ratification.
OF WHICH / THE [NOUN] OF WHICH: formal alternative for relative clauses with objects, preferred in VERY FORMAL or legal/academic English when one wishes to avoid WHOSE for things. STRUCTURES: (1) THE + [noun] + OF WHICH: "The contract, the terms of which had been under negotiation for months, was finally signed." (2) [NOUN] + OF WHICH (prepositional clause): "The strategy, the success of which depends on market timing, will be reviewed quarterly." OF WHICH is MORE FORMAL and LONGER than WHOSE. In contemporary English, even in academic and legal texts, WHOSE is widely accepted for objects. OF WHICH is the option for those who want a very formal and explicit style.
The partnership agreement, the specific terms of which remain confidential under the mutual non-disclosure obligations signed by both parties, represents a strategic milestone for the division.
The research methodology, the rigor and validity of which will be independently assessed by an external academic panel, has already received preliminary endorsement from the scientific advisory board.
The board reviewed three transformation scenarios, the financial implications of which varied significantly depending on the assumed timeline for market recovery.
Common mistake
THE MAIN ERROR: believing WHOSE is only valid for people. "The building who's roof is damaged" = INCORRECT (WHO instead of WHOSE + additional error: "who's" = "who is," not possessive). For objects: "The building WHOSE roof is damaged" = correct. "The building the roof of which is damaged" = also correct (formal). Second error: confusing WHOSE with WHO'S. WHOSE = possessive relative (no apostrophe). WHO'S = contraction of "who is" or "who has" (with apostrophe). "The manager who's responsible" = "the manager who IS responsible." "The manager whose decision was final" = WHOSE = possessive.
Trick to remember it
SUBSTITUTION TEST: substitute the relative clause with a direct possessive. "The company WHOSE shares are listed" = "The company's shares are listed." If you can make that substitution with a possessive, the relative clause uses WHOSE (for people) or WHOSE / OF WHICH (for things). WHOSE vs WHO'S: WHOSE = without apostrophe (possessive). WHO'S = with apostrophe (who is / who has). Test: substitute with "who is" or "who has" — if it makes sense = WHO'S. If not = WHOSE. "The manager WHOSE performance..." = "the manager WHO IS performance..." makes no sense = it is WHOSE (possessive). "The manager WHO'S in charge" = "the manager WHO IS in charge" = makes sense = WHO'S (contraction).
Quick rule
Whose = possessive relative for PEOPLE AND THINGS (both correct in modern English). Of which = formal alternative for THINGS. Whose (no apostrophe) = possessive. WHO'S (with apostrophe) = "who is/has" (not possessive). Test: can you put "[noun]'s"? = use whose.
Did you know?
The "rule" that WHOSE can only refer to people has been debated and rejected by English grammarians since at least the 18th century. However, it continues to appear in outdated style manuals and grammar books, which perpetuates it among learners. In reality, the greatest classic authors of English literature used WHOSE for objects freely: John Milton and Shakespeare both used WHOSE for non-personal references repeatedly. The "rule" against WHOSE for things is a classic example of PRESCRIPTIVE HYPERCORRECTION — a rule invented by 18th-century grammarians who tried to purify English with pseudo-Latin rules, even though actual language use had never had that restriction.
Exercise 1 · Pick the right one
The pharmaceutical company _____ patent portfolio includes over three hundred active compounds in various stages of clinical development announced a record licensing revenue for the fiscal year.
Exercise 2 · Pick the right one
The three-year strategic roadmap, _____ full implementation depends on securing Series B funding and regulatory clearance in at least two major markets, was presented to the board.
Exercise 3 · Form the word
Whose = possessive relative for PEOPLE AND THINGS (both correct in modern English). Of which = formal alternative for THINGS. Whose (no apostrophe) = possessive. WHO'S (with apostrophe) = "who is/has" (not possessive). Test: can you put "[noun]'s"? = use whose.
THE MAIN ERROR: believing WHOSE is only valid for people. "The building who's roof is damaged" = INCORRECT (WHO instead of WHOSE + additional error: "who's" = "who is," not possessive). For objects: "The building WHOSE roof is damaged" = correct. "The building the roof of which is damaged" = also correct (formal). Second error: confusing WHOSE with WHO'S. WHOSE = possessive relative (no apostrophe). WHO'S = contraction of "who is" or "who has" (with apostrophe). "The manager who's responsible" = "the manager who IS responsible." "The manager whose decision was final" = WHOSE = possessive.
SUBSTITUTION TEST: substitute the relative clause with a direct possessive. "The company WHOSE shares are listed" = "The company's shares are listed." If you can make that substitution with a possessive, the relative clause uses WHOSE (for people) or WHOSE / OF WHICH (for things). WHOSE vs WHO'S: WHOSE = without apostrophe (possessive). WHO'S = with apostrophe (who is / who has). Test: substitute with "who is" or "who has" — if it makes sense = WHO'S. If not = WHOSE. "The manager WHOSE performance..." = "the manager WHO IS performance..." makes no sense = it is WHOSE (possessive). "The manager WHO'S in charge" = "the manager WHO IS in charge" = makes sense = WHO'S (contraction).
Bryan López
Founder of SpeakUP Academy