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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
in under
Grammar usage guide and real-world examplesUSAGE SUMMARY
"In under" is an informal phrase and is not usually used in written English. It is more common to use "within" or "in less than" instead. For example, "We need to get this finished in under an hour."
News & Media
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
49 human-written examples
arrives in under seven seconds.
News & Media
Fight stopped in under two minutes.
News & Media
In under an minute.
News & Media
In under the shelter.
News & Media
All in under four hours.
News & Media
Wraps up in under 20 seconds.
News & Media
Human-verified similar examples from authoritative sources
Similar Expressions
10 human-written examples
Malnutrition prevalence in under-fives is 27%.
News & Media
"Being 25-0 doesn't happen at any level, in Under-18 soccer, in Under-18 volleyball.
News & Media
We strongly believe in "under-promising and over-deliving".
News & Media
This may result in under-reporting.
Science
Great run-in under pressure.
News & Media
Expert writing Tips
Best practice
While "in under" is acceptable in informal contexts, consider using more precise alternatives like "within" or "in less than" for formal writing to enhance clarity and professionalism.
Common error
Avoid using "in under" in academic papers or business reports. Opt for phrases like "within" or "in a period less than" to maintain a formal tone and avoid ambiguity.
Source & Trust
84%
Authority and reliability
3.8/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "in under" functions as a prepositional modifier, typically indicating that an action, event, or process occurs within a certain timeframe or below a specific limit. As Ludwig AI reports, it's an informal phrase.
Frequent in
News & Media
88%
Wiki
4%
Science
4%
Less common in
Formal & Business
0%
Academia
0%
Encyclopedias
0%
Ludwig's WRAP-UP
The phrase "in under" is a prepositional phrase used to denote that something occurs within a certain time frame or below a specific limit. While commonly used, as shown by Ludwig's examples, it is generally considered informal. Ludwig AI suggests opting for alternatives like "within" or "in less than" in more formal contexts. The primary contexts where this phrase appears are news and media sources. While acceptable in casual conversation, it's advisable to use more precise language for academic or professional writing to ensure clarity.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
less than
Directly states that a quantity is smaller than a specific value.
within
Suggests being contained inside a time frame or limit.
in less than
More explicit and formal way of indicating that something happens before a certain time.
before
Simple preposition indicating precedence in time.
prior to
A more formal alternative to "before", indicating a time precedence.
sooner than
Emphasizes the quickness or earliness of an event.
earlier than
Similar to "sooner than", but less emphatic.
shorter than
Used to indicate duration, focusing on brevity.
not exceeding
Indicates a maximum limit that should not be surpassed.
below
While primarily spatial, it can metaphorically refer to amounts or limits.
FAQs
What does "in under" mean?
The phrase "in under" generally means within a specified duration or below a certain threshold. For example, "The task was completed in under an hour" means it took less than one hour.
When is it appropriate to use "in under"?
It's appropriate in casual conversation or informal writing. However, in formal or academic contexts, it's better to use more precise and formal alternatives such as "within" or "in less than".
Is "in under" grammatically correct?
While commonly used, "in under" isn't considered strictly grammatically correct in formal English. It's a more colloquial way of expressing that something is completed or achieved before a certain time or quantity.
What are some alternatives to "in under" that I can use?
Depending on the context, you can use alternatives like "within", "in less than", or simply "less than". For example, instead of "The project was finished in under two weeks", you can say "The project was finished within two weeks".
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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
84%
Authority and reliability
3.8/5
Expert rating
Real-world application tested