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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
per change
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "per change" is not correct and is not commonly used in written English.
It is unclear what you intend to convey with "per change," as it does not have a standard meaning or usage in English. Example: "The policy will be updated per change in regulations." (This is incorrect; a better phrase would be used.)
⚠ May contain grammatical issues
Science
News & Media
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 examples from authoritative sources
Exact Expressions
34 human-written examples
This bounty came after most of the industry (minus Southwest) tacitly agreed to create a new industry standard of two hundred dollars per change, plus, in some cases, an additional fifty-dollar service fee for tickets booked on non-airline Web sites.
News & Media
The batteries, if you can believe it, last 3 years per change.
News & Media
While not contributing much more fuel economy per change in load fraction than the drive system per change in efficiency, tractive load reduction stands out as the largest untapped source of fuel economy improvement.
The hip RP was defined as the angular position in which the passive joint torque equals zero, and passive hip stiffness was calculated as the change in passive torque per change in joint angle.
Science
Under reasonable assumptions on the motion, we show that the total number of times this BSP changes is O(n2), and that we can update the BSP in O logn) expected time per change.
Science
Abdominal compliance (CAB) was defined as a measure of the ease of abdominal expansion, expressed as a change in intra-abdominal volume (IAV) per change in intra-abdominal pressure (IAP): AC = ΔIAV/ΔIAP [1].
Human-verified similar examples from authoritative sources
Similar Expressions
26 human-written examples
Below we provide our detailed response to specific comments per changes made in the updated version of the manuscript.
Science
And there might be a two-per-cent change".
News & Media
Under typical experimental conditions, beat rate varied approximately 10% per degree change in temperature or per 0.1 unit change in pH.
Steve Politi of The Star-Ledger wonders if Girardi gets paid per pitching change.
News & Media
Argon leakage may fractionate the remaining 40Ar/36Ar ratio by +0.007‰ per ‰ change in 84Kr/36Ar, introducing a possible bias in reconstructed firn thickness of about +2 m if thermal diffusion is not accounted for or +6 m if thermal diffusion effects are quantified with measured 15N/14N.
Expert writing Tips
Best practice
When describing rates or proportions, replace "per change" with more precise language such as "for each change", "with every change", or "per unit change" to ensure clarity.
Common error
Avoid using "per change" in formal writing assuming it's a universally accepted phrase. While it appears in some contexts (particularly scientific), it's often better replaced with clearer alternatives like "for each change" or "with every change" to prevent confusion.
Source & Trust
82%
Authority and reliability
2.8/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "per change" functions primarily as a prepositional phrase attempting to express a ratio or rate of change. As Ludwig indicates, this construction is not considered standard English, suggesting alternative phrasing for clarity.
Frequent in
Science
73%
News & Media
24%
Wiki
3%
Less common in
Formal & Business
0%
Encyclopedias
0%
Reference
0%
Ludwig's WRAP-UP
In summary, while the phrase "per change" appears in some contexts, particularly scientific ones, it is not considered standard English. Ludwig underscores that it is incorrect and should be replaced with clearer alternatives. Common replacements include "for each change", "with every change", or "per unit change", depending on the specific meaning you intend to convey. Predominantly found in scientific and news-related articles, its use in formal writing should be approached with caution. To ensure clear and grammatically correct communication, using alternative phrases is highly recommended.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
for each change
Replaces "per change" with a clearer and more universally understood prepositional phrase.
with every change
Emphasizes the iterative nature of the change, suitable when each individual change is important.
per unit change
More specific, indicating a standardized or quantifiable change.
for a change in
Indicates a cause or reason, rather than a direct relationship of change.
in response to change
Highlights the reactive nature of an action following a change.
corresponding to each change
A more formal and precise way to express a direct correlation between changes.
as a result of change
Focuses on the outcome or consequence of a change.
due to changes in
Explains that changes are the reason of something.
in light of changes
Indicates that changes have led to a new perspective or action.
based on changes
Expresses that something relies upon the changes made.
FAQs
What does "per change" mean in a scientific context?
In scientific contexts, "per change" often refers to the amount of variation in one variable relative to a change in another, typically expressed as a ratio. For clearer communication, consider using phrases like "change in Y per change in X" or "Y varies with X".
What can I say instead of "per change"?
Depending on the context, you can use alternatives like "for each change", "with every change", or "per unit change" for clearer and more standard English.
Is "per change" grammatically correct in formal writing?
While "per change" appears in some technical contexts, it is not considered standard English for general use. Using alternatives like "for each change" is recommended for formal writing.
How does "per change" compare to "for each change"?
"For each change" is generally preferred over "per change" because it's more explicit and universally understood. While "per change" may be acceptable in specific technical domains, "for each change" provides greater clarity in most situations.
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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
82%
Authority and reliability
2.8/5
Expert rating
Real-world application tested