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
he deduces that
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "he deduces that" is correct and usable in written English.
It can be used when indicating that someone has drawn a conclusion based on reasoning or evidence. Example: "After analyzing the data, he deduces that the experiment was a success."
✓ Grammatically correct
News & Media
Wiki
Encyclopedias
Alternative expressions(6)
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
14 human-written examples
Talking about "that dimension of intersubjectivity on which Epicureanism (and Leibnizianism too, for that matter) founders," he deduces that "what is in one today will be in another tomorrow, that by the end of our exchanges that which forms part of my essence at the moment of my writing to you may perhaps have entered yours".
News & Media
"He deduces that killing a human is right in pursuit of a higher cause," she tells Grant.
News & Media
Tintinologists cannot get enough of these buried treasures, and I applaud Tom McCarthy for the logical rigor with which he deduces that the jewel embedded in the title of "The Castafiore Emerald" is, in fact, Bianca Castafiore's clitoris.
News & Media
From the failures of the Arab Spring, he deduces that it would have been better to leave Hosni Mubarak in power in Egypt and try to affect a more gradual transition.
News & Media
He deduces that Jin-xi cannot possibly be the bumbling bumpkin he pretends to be, but must rather be a lost member of the dreaded 72 Demons gang, which soon shows up, making inquiries of its own.
News & Media
But Sperber's rigor also yields gems, as when he deduces that the Marxes must have conceived their first child in the summer of 1843, while on a visit to Marx's mother-in-law.
News & Media
Human-verified similar examples from authoritative sources
Similar Expressions
46 human-written examples
He deduced that instead of one continuous population of cod that moved, there seemed to be several sub-populations.
News & Media
When he was still in his 20's, he deduced that mysterious radio emissions from Venus were caused by surface temperatures around 900 degrees Fahrenheit and that the planet had a crushing atmosphere.
News & Media
Nevertheless, Mr. Cusack said, in piecing together the records, he deduced that Kennedy initially sought counsel on matters of church and state -- Kennedy was hoping to become the first Roman Catholic president, and did so in 1961.
News & Media
He deduced that Reyes needed a cleaner swing.
News & Media
Here he deduced that electromagnetic radiation itself consists of "particles" of energy hν.
Encyclopedias
Expert writing Tips
Best practice
Use "he deduces that" when you want to emphasize a logical inference drawn by a specific person based on available evidence or reasoning.
Common error
Avoid using "he deduces that" in casual or informal contexts. Simpler alternatives like "he thinks" or "he figures" may be more appropriate depending on the tone you want to achieve.
Source & Trust
86%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "he deduces that" functions as a reporting clause, introducing a statement that represents someone's deduction or conclusion. It connects the person ("he") with the conclusion they have reached through reasoning. Ludwig's examples show how this phrase is used to convey a character's understanding or inference.
Frequent in
News & Media
40%
Wiki
30%
Encyclopedias
10%
Less common in
Science
10%
Academia
0%
Formal & Business
0%
Ludwig's WRAP-UP
The phrase "he deduces that" serves to report a conclusion someone has drawn through reasoning, as affirmed by Ludwig. While grammatically sound, its frequency is uncommon, leaning towards neutral to formal contexts like news, encyclopedias, and analytical writing. Alternatives such as "he infers that" or "he concludes that" offer similar meanings. When employing the phrase, prioritize clarity and avoid its use in informal settings. With an expert rating of 4.5, it stands as a reliable but not ubiquitous element of the English language.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
he infers that
Replaces "deduces" with "infers", suggesting a conclusion based on reasoning from evidence.
he concludes that
Uses "concludes" instead of "deduces", indicating a final judgment or decision reached after consideration.
he reasons that
Emphasizes the logical process involved in reaching the conclusion.
he infers from this that
Highlights the connection between the observed information and the deduction.
he gathers that
Implies the conclusion is formed from collected information or observations.
he understands that
Suggests comprehension leading to a specific conclusion.
he determines that
Indicates a more definitive and certain conclusion.
he ascertains that
Suggests careful and thorough investigation leading to the conclusion.
he figures out that
A more informal way of saying "he deduces that", implying a problem-solving approach.
it is his deduction that
Changes the sentence structure to emphasize the deduction itself.
FAQs
What does "he deduces that" mean?
The phrase "he deduces that" means that someone has come to a conclusion based on reasoning or evidence. It implies a logical process of inference.
What can I say instead of "he deduces that"?
You can use alternatives like "he infers that", "he concludes that", or "he reasons that" depending on the specific nuance you want to convey.
Is it correct to say "he deduced that"?
Yes, "he deduced that" is the past tense form and is grammatically correct. "He deduces that" is present tense.
What's the difference between "he deduces that" and "he assumes that"?
"He deduces that" implies a logical conclusion based on evidence, while "he assumes that" suggests a belief or supposition without necessarily having solid evidence.
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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
86%
Authority and reliability
4.5/5
Expert rating
Real-world application tested