English grammar can sometimes be confusing, especially when it comes to relative pronouns and phrases such as ‘of whom’ and ‘of which.’ Both phrases serve to introduce relative clauses, providing additional information about a noun previously mentioned. However, their usage depends largely on whether the noun refers to people or things, as well as on formality and sentence structure. Mastering when to use ‘of whom’ versus ‘of which’ is important for clear and grammatically correct writing and speaking. This topic explores the difference between these two expressions, provides clear examples, and offers practical tips for usage in everyday English.
The Role of ‘Of Whom’ in English
‘Of whom’ is a formal relative pronoun phrase used exclusively to refer to people or sometimes animals when personified. It is the object form of ‘who’ combined with the preposition ‘of.’ This phrase usually appears in more formal or written English, often within relative clauses that provide additional information about a person or group.
For example:
- ‘The students,of whomseveral were absent, took the exam today.’
- ‘She is a teacherof whommany students think highly.’
- ‘The committee,of whomtwo members resigned, will meet tomorrow.’
In these examples, ‘of whom’ links back to people (students, teacher, committee members), showing possession or association in a formal way.
When to Use ‘Of Which’
‘Of which’ is used similarly but applies to non-human nouns objects, animals (non-personified), concepts, or groups of things. It introduces relative clauses that give more information about these inanimate or abstract nouns. Like ‘of whom,’ it combines the preposition ‘of’ with the relative pronoun ‘which.’
Examples of ‘of which’ include:
- ‘The book,of whichseveral copies were sold, is now out of print.’
- ‘They live in a houseof whichthe roof needs repair.’
- ‘The project,of whichthe details are confidential, will begin next year.’
In these sentences, ‘of which’ refers to things or concepts (book, house, project), not people.
Key Differences Between ‘Of Whom’ and ‘Of Which’
- Reference: ‘Of whom’ refers exclusively to people (or personified beings), whereas ‘of which’ refers to things, animals (non-personified), or abstract ideas.
- Formality: Both are considered formal expressions and are common in written English; less formal speech often prefers simpler structures.
- Sentence Structure: Both are used to introduce relative clauses following a noun phrase, typically to add descriptive or possessive information.
- Preposition Use: The ‘of’ indicates possession, origin, or association, combined with the appropriate relative pronoun (‘whom’ for people, ‘which’ for things).
Examples Illustrating the Difference
To better understand, consider the following pairs of sentences:
- People: ‘The doctors,of whommany specialize in cardiology, attended the conference.’
(Correct because doctors are people.) - Things: ‘The paintings,of whichseveral were stolen, are priceless.’
(Correct because paintings are objects.) - Incorrect: ‘The players,of whichsome are injured, cannot participate.’
(Incorrect because players are people, so ‘of whom’ should be used.) - Incorrect: ‘The computer,of whomthe parts are broken, is new.’
(Incorrect because a computer is a thing, so ‘of which’ should be used.)
Alternative Constructions
In less formal English, speakers often avoid ‘of whom’ and ‘of which’ by restructuring sentences. This is especially common in spoken language, where such formal phrases might sound too stiff or complicated.
- Instead of: ‘The teachers, of whom many have PhDs, are dedicated.’
Say: ‘Many of the teachers have PhDs.’ - Instead of: ‘The documents, of which some were lost, are important.’
Say: ‘Some of the documents were lost.’
These alternatives make sentences simpler and more natural in everyday conversation, though the formal versions are preferable in academic or professional writing.
Common Mistakes to Avoid
- Using ‘of which’ when referring to people instead of ‘of whom.’
- Omitting the preposition ‘of’ when it is necessary: Saying ‘whom’ or ‘which’ alone when ‘of whom’ or ‘of which’ is required.
- Confusing ‘whom’ with ‘who’ ‘whom’ is the object form and generally used after a preposition like ‘of.’
Quick Tips to Remember
- If referring to people or personified beings, useof whom.
- If referring to things, objects, or abstract ideas, useof which.
- Both are formal, so consider sentence context and audience.
- Rearrange sentences in casual writing to avoid awkward phrasing.
Why Understanding These Phrases Matters
Mastering ‘of whom’ and ‘of which’ improves both writing and speaking skills by enabling clearer, more precise expression. These phrases help avoid ambiguity and demonstrate a higher level of grammatical accuracy. Especially in academic writing, formal reports, and professional communication, using the correct relative pronouns shows attention to detail and language competence.
Moreover, knowing the difference is useful for understanding complex sentences in literature, legal documents, and technical writing, where precision matters greatly.
Summary
The phrases ‘of whom’ and ‘of which’ are essential tools in English grammar for forming relative clauses that give additional information about nouns. The main distinction is that ‘of whom’ refers to people, while ‘of which’ refers to things or abstract concepts. Both are formal constructions primarily found in writing but can be used in speech for emphasis or clarity. By recognizing their correct usage and practicing with examples, English learners and speakers can enhance their command of the language and avoid common mistakes.