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Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
which occur
Grammar usage guide and real-world examplesUSAGE SUMMARY
The part of the sentence "which occur" is correct and usable in written English.
You can use it when referring to something that happens or appears regularly. For example: The weather in this region has frequent rain showers which occur every evening.
✓ Grammatically correct
Alternative expressions(2)
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified similar examples from authoritative sources
Similar Expressions
58 human-written examples
Which A5?
News & Media
Speaking of which: 3.
News & Media
Which 60-gigahertz technology will prevail?
News & Media
Qf7!, after which 25 Bc6?
News & Media
Which 14 positions?
News & Media
Which 50s classic to choose?
News & Media
Which 15 would you take?
News & Media
miles, of which 1.24 sq.
(f4!) after which 29 b4! cracked the defences.
News & Media
So, which 14 lines would you choose?
News & Media
Of which 204,000 (53%) have dependent children.
News & Media
Expert writing Tips
Best practice
Use "which occur" to introduce nonrestrictive clauses that provide additional information about a noun or event, ensuring the clause is set off with commas.
Common error
Avoid using "which occur" in restrictive clauses (those essential to the sentence's meaning). In such cases, "that occur" is generally preferred. Use "which occur" only for nonrestrictive clauses, which add extra information and are set off by commas.
Source & Trust
60%
Authority and reliability
3.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "which occur" functions as a relative pronoun + verb construction, introducing a nonrestrictive relative clause. It provides additional, non-essential information about a preceding noun or noun phrase. Ludwig indicates its grammatical correctness.
Frequent in
Science
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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, the phrase "which occur" serves as a relative clause introducer, adding descriptive details about preceding nouns or events. While grammatically sound, according to Ludwig, it's essential to distinguish its use in nonrestrictive clauses from the use of "that" in restrictive clauses. Alternatives like "that happen" may be suitable for less formal contexts. Due to the lack of specific examples in the provided data, assessing its frequency and typical usage patterns is challenging, but Ludwig's AI confirms its grammatical correctness and usability.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
that happen
Replaces "occur" with the more common verb "happen", slightly reducing formality.
that take place
Substitutes "occur" with the phrase "take place", offering a more descriptive alternative.
that arise
Replaces "occur" with "arise", suggesting a more spontaneous or unexpected appearance.
that transpire
Offers a more formal and less frequent synonym for "occur".
that come about
Replaces "occur" with a phrasal verb, indicating a process or sequence of events.
that unfold
Implies a gradual revelation or development, adding a narrative quality.
that present themselves
Suggests opportunities or situations that become available.
that materialize
Implies the realization of something that was previously abstract or conceptual.
that ensue
Indicates events that follow as a consequence or result.
that follow
A simpler and more direct way to indicate events that happen after something else.
FAQs
How do I use "which occur" in a sentence?
Use "which occur" to introduce a nonrestrictive clause that provides additional information about something already mentioned. For example, "The weather patterns, "which occur" frequently in this region, can be unpredictable."
Is "which occurs" or "that occurs" better?
In general, "that occurs" is preferred for restrictive clauses (essential to the sentence's meaning), while "which occurs" is used for nonrestrictive clauses (additional, non-essential information). However, using "which occur" to refer to multiple items is grammatically correct.
What's the difference between "which happen" and "which occur"?
"Which happen" and "which occur" are largely interchangeable, with "which occur" being slightly more formal. Consider using "which happen" in casual contexts and "which occur" in more formal writing.
What can I say instead of "which occur"?
You can use alternatives like "that happen", "that take place", or "which arise" depending on the specific context.
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
60%
Authority and reliability
3.5/5
Expert rating
Real-world application tested