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
that's
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "that's" is correct and usable in written English.
It is a contraction of "that is" or "that has" and can be used in various contexts to provide clarification or emphasis. Example: "I can't believe that's the final decision on the project."
✓ Grammatically correct
Science
Alternative expressions(11)
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
60 human-written examples
Good boy, that's fantastic.
Science
E: Yeah, that's fun.
Science
That's Jenike".
Science
That's important.
That's good.
Science
That's easy.
That's great.
Science
That's ethnography.
Science
That's it.
That's science".
"That's the whole point though, that's science.
Expert writing Tips
Best practice
Use "that's" in informal writing and speech to create a conversational tone. Avoid in formal academic papers.
Common error
Avoid using "that's" when you should be using "those". "That's" is a contraction of "that is" or "that has", while "those" is a plural demonstrative pronoun.
Source & Trust
80%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The primary function of "that's" is to express agreement, confirmation, or affirmation. As a contraction of "that is", it often serves as a concise way to acknowledge or validate a statement or situation. Ludwig provides numerous examples illustrating its use in diverse contexts.
Frequent in
Science
100%
Less common in
News & Media
0%
Formal & Business
0%
Academia
0%
Ludwig's WRAP-UP
In summary, the phrase "that's" is a grammatically sound contraction of "that is" or "that has", commonly used in spoken and written English to express agreement, confirmation, or explanation. Ludwig AI indicates its frequent occurrence, particularly within scientific contexts. While generally informal, "that's" is versatile, but should be used cautiously in formal writing where expanding the contraction may be more appropriate. Be mindful not to confuse it with "those", a plural demonstrative pronoun.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
that is
Expands the contraction to its full form, offering a more formal tone.
that has
Expands the contraction to its full form, indicating possession or completion.
it is
Similar in function but refers to a different subject.
it's
Contraction of "it is", providing a similar level of informality.
this is
Shifts the focus to something closer or more immediate.
this means
Introduces an explanation or clarification.
in other words
Provides an alternative way of stating something.
specifically
Introduces a specific detail or example.
namely
Highlights a particular item or aspect.
for instance
Introduces an example to illustrate a point.
FAQs
What's the difference between "that's" and "that is"?
"That's" is a contraction of "that is". Using "that's" is generally more informal, while "that is" is more formal and suitable for academic or professional writing.
When should I use "that's" versus "that has"?
Use "that's" when you mean "that is", like in "That's a great idea!". When you mean "that has", such as "The company that's been struggling", also use "that's". The context usually makes the meaning clear.
Are there situations where I should avoid using "that's"?
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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
80%
Authority and reliability
4.5/5
Expert rating
Real-world application tested