Used and loved by millions
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
number of sunlight
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "number of sunlight" is not correct in standard written English.
It is typically used incorrectly when referring to the amount or intensity of sunlight, which is better expressed in different terms. Example: "The number of sunlight hours in this region affects the growth of crops."
⚠ May contain grammatical issues
Science
News & Media
Wiki
Alternative expressions(5)
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
2 human-written examples
Instead, we used the average monthly number of sunlight hours in Valencia from 1938 to 1990, covering most of the exposure period for the study participants [ 17], to account for differences in summer and winter exposures.
Science
Although there is currently enormous research investment into the bulk production of microalgae for biodiesel, photo bioreactors are unlikely to be economically competitive for bioenergy production, and culture in outdoor ponds is only suited to regions with a relatively high number of sunlight hours and even then may still be uncompetitive in the biofuels market [ 9].
Science
Human-verified similar examples from authoritative sources
Similar Expressions
55 human-written examples
But a bit of sunlight is creeping in.
News & Media
Utilizing data collected on the number of hours of sunlight exposure experienced on a typical weekday and weekend day during the summer in different time periods, summary scores were calculated.
Science
(Source: LocClim database developed by the Food and Agriculture Organization, ), including rainfall (in mm), temperature (in °C), evapotranspiration (in mm), relative humidity (i.e., water vapour pressure in % saturation), mean number of hours of sunlight per day, and wind speed (in m.s-1).
Science
If you have been germinating the seed in a low-sun area, you will need to move it into the sun and slowly increase the number of hours of sunlight.
Wiki
The book is a tour de force, showing, for example, how the potential contribution of biofuels can be approximated from just three numbers: the intensity of sunlight, the efficiency with which plants turn that sunlight into stored energy and the available land area in Britain.
News & Media
Phenotypic characteristics (e.g. hair, eye and skin colour, skin sensitivity to sunlight, number of nevi (moles)), family history, past sun exposure and past history of skin cancer are usually the basis for discriminating individual risk of melanoma [ 5- 7].
Science
However, if the reported number of hours of weekday sunlight exposure was less than that of weekend sunlight exposure, then the participant was considered as having intermittent sunlight exposure.
Science
In "New theory about light and colors", published in the Philosophical Transactions in 1672, Newton presented a number of experiments in which sunlight was allowed to pass through one or two prisms in order to probe some of its basic features.
Science
SF authors and historians Brian Aldiss and David Wingrove summarize Galaxys history by saying that it lasted for "thirty mainly glorious years": it "brought into the sunlight a number of excellent satirists, comedians and ironists" and, through the influence of its reduced focus on technology, played an important role in attracting women to write science fiction.
Wiki
Expert writing Tips
Best practice
When discussing light exposure, use more precise terms such as "amount of sunlight", "intensity of sunlight", or "hours of sunlight" to ensure clarity and grammatical accuracy.
Common error
Avoid using "number of sunlight" to describe the quantity or intensity of sunlight. This phrasing is not standard English. Instead, opt for expressions like "amount of sunlight" or "intensity of sunlight".
Source & Trust
82%
Authority and reliability
2.8/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "number of sunlight" functions as a noun phrase, although it is generally considered grammatically incorrect. Ludwig AI indicates that it is not correct in standard written English, and suggests alternatives focusing on "amount" or "intensity".
Frequent in
Science
30%
News & Media
25%
Wiki
20%
Less common in
Formal & Business
10%
Encyclopedias
5%
Reference
10%
Ludwig's WRAP-UP
In summary, while the phrase "number of sunlight" appears in some contexts, Ludwig AI identifies it as grammatically incorrect in standard written English. It's generally recommended to use alternatives like "amount of sunlight", "intensity of sunlight", or "hours of sunlight" for greater clarity and accuracy. The phrase is relatively uncommon, primarily found in science and news media, but should be avoided in formal writing. Using precise and accepted terminology enhances communication and avoids grammatical errors.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
amount of sunlight
Replaces "number" with "amount", focusing on the quantity of sunlight received.
intensity of sunlight
Focuses on the strength or power of the sunlight.
duration of sunlight
Emphasizes the length of time sunlight is present.
hours of sunlight
Specifies the measurement of sunlight in terms of time.
sunlight exposure level
Highlights the degree to which something is exposed to sunlight.
solar irradiance
Technical term for the power of sunlight per unit area.
sunlight availability
Focuses on whether sunlight is present or accessible.
level of solar radiation
Scientifically accurate way to describe the measurement of sunlight.
sunlight frequency
How often sunlight is present in a specific location.
solar energy intensity
Focuses on the strength of the sun's energy.
FAQs
What's a better way to say "number of sunlight"?
Instead of "number of sunlight", use more common and grammatically correct alternatives such as "amount of sunlight", "intensity of sunlight", or "hours of sunlight" depending on the context.
Is "number of sunlight" grammatically correct?
The phrase "number of sunlight" is generally considered grammatically incorrect in standard English. It's better to use phrases like "amount of sunlight" or "intensity of sunlight".
How does "amount of sunlight" differ from "number of sunlight"?
"Amount of sunlight" refers to the quantity of solar radiation, while "number of sunlight" is not a standard or grammatically correct phrase. Therefore, "amount of sunlight" is the preferred way to describe how much sun there is.
When should I use "hours of sunlight" instead of "number of sunlight"?
Use "hours of sunlight" when you're referring to the duration of time that sunlight is present in a specific location. The phrase "number of sunlight" is not grammatically sound.
Editing plus AI, all in one place.
Stop switching between tools. Your AI writing partner for everything—polishing proposals, crafting emails, finding the right tone.
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