both of which

USAGE SUMMARY

"both of which" is correct and usable in written English.
You can use it to refer to two things that have already been mentioned or that are already known to the reader. For example: "The teacher gave the students two assignments, both of which needed to be completed by the end of the week."

✓ Grammatically correct

Science

News & Media

Formal & Business

Human-verified similar examples from authoritative sources

Similar Expressions

59 human-written examples

Coordination polymers 2 and 2a, both made of [AgL2]+ repeating unit, contains different conformers of L2.

Polyhedron

NW21, Sherly Santaskas of 270 Washington Street, Somerville and Perry Redell and Kurt Bennett, both of 240 Albany Street, Cambridge, arrested for trespassing.

Massachusetts Institute of Technology

Two other suspects, Wisdom Champaign, 18, and Misten Champaign, 19, both of 514 West 134th Street, were not wounded.

The New York Times

We and others previously reported that both of USP4 and USP11 function in DNA repair.

Nature

Keith Boyer, 45, and Roberta Boyer, 39, both of 148th Street, were charged with criminal possession of a weapon, the police said.

The New York Times

We identify that both of JAK2 and SOSC3 have m6A modification at 3′UTR by m6A-seq analysis.

Nature

The space group was P¯1 for both of 10 GT and 20 GT.

Polymer

The suspects were identifiedas Anthony Mack, 18 years old, and Vernon Ricks, 24, both of 2240 Mott Avenue in Far Rockaway.

The New York Times

In contrast, the council's 2014-15 budgivesives a combined running cost for both of £874 a day.

The Guardian - Books

Victoria's main ski fields of Falls Creek and Mount Hotham recorded falls of 34cm and 25cm respectively in 24 hours, adding to a total snow depth on both of 82cm.

The Guardian

The others arrested yesterday were identified as Kevin Quinn, 29, of 157 Carroll Street, the Bronx; his brother, Timothy, 28, and Debra Castello, 23, both of 617 Clarence Avenue, the Bronx.

The New York Times

Expert writing Tips

Best practice

Use "both of which" to clearly connect two elements already introduced in your writing, enhancing flow and avoiding repetition.

Common error

Avoid using "both of which" when referring to a single item or concept. This phrase is exclusively for referencing two distinct entities previously mentioned.

Linguistic Context

The phrase "both of which" functions as a relative pronoun construction. It connects a main clause to a non-defining relative clause, providing additional information about two previously mentioned nouns or noun phrases. Ludwig AI indicates this phrase is grammatically sound.

Expression frequency: Missing

Frequent in

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News & Media

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Formal & Business

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Less common in

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Ludwig's WRAP-UP

In summary, "both of which" is a grammatically correct and useful phrase for adding detail about two previously mentioned items, as affirmed by Ludwig. Though current data indicates limited examples, it's a formal way to link clauses and enhance clarity. Consider "both of whom" when referring to people, and avoid using it with singular nouns. Despite its grammatical correctness, explore alternative expressions to maintain a varied and engaging writing style. Although there are no authoritative sources or frequent usage patterns at this time, this does not detract from its validity as a grammatical form.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

both of whom

Replaces 'which' with 'whom', suitable when referring to people.

both of the things

Substitutes 'which' with a more explicit noun phrase, adding emphasis.

both of these

Uses a demonstrative pronoun to refer to previously mentioned items.

in both cases

Highlights that two scenarios share a common attribute.

both aspects

Focuses on two specific elements or features under consideration.

both items

Replaces 'which' with 'items' referring to two specific things.

of both

A more concise version, suitable when the context is very clear.

both alternatives

Highlights that two options or choices exist.

each of which

Similar, but emphasizes individual characteristics rather than the pair.

both of the aforementioned

Adds formality by explicitly referencing what was previously mentioned.

FAQs

How can I use "both of which" in a sentence?

Use "both of which" to refer back to two things you've already mentioned. For instance, "The company released two new products, "both of which" are designed for home use."

What's a simple substitute for "both of which"?

Depending on the context, you might use "and "both"", "both of these", or rephrase the sentence for clarity.

Is it correct to use "both of which" when referring to people?

While grammatically correct, it's more common to use "both of whom" when referring to two people. For example, "The team consists of two members, both of whom are experts in their fields."

How does "both of which" differ from "each of which"?

"Both of which" refers to two items together, while "each of which" emphasizes the individual characteristics of more than two items. For example, "The store sold several types of cookies, each of which had a unique flavor."