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 is so
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "that is so" is correct and usable in written English.
It is typically used to express agreement, acceptance, or affirmation. For example, "I think this is the best solution." "That is so."
✓ Grammatically correct
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
60 human-written examples
DANA SPIOTTA: Candice, that is so lovely.
News & Media
Her mother assures her that is so.
News & Media
Make another "V" that is so wide.
Wiki
And that is so.
News & Media
"That is so him.
News & Media
That is so dumb.' ".
News & Media
"That is so sweet.
News & Media
That is so over.
News & Media
That is so liberating.
News & Media
That is so Coppola.
News & Media
That is so wrong.
News & Media
Expert writing Tips
Best practice
Use "that is so" to express strong agreement or affirmation, ensuring it aligns with the tone of the conversation or writing.
Common error
Avoid overuse of "that is so" in formal writing, as it can sound too casual. Opt for more formal alternatives like "indeed" or "that is correct" to maintain a professional tone.
Source & Trust
89%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "that is so" functions primarily as an affirmative expression, confirming or validating a previous statement. As Ludwig AI indicates, it conveys agreement or acceptance. Examples show its use in direct responses to assertions, reinforcing their truth or accuracy.
Frequent in
News & Media
70%
Wiki
15%
Formal & Business
5%
Less common in
Science
3%
Encyclopedias
2%
Academia
5%
Ludwig's WRAP-UP
In summary, the phrase "that is so" is a common and generally correct expression used to convey agreement or affirmation. As Ludwig AI confirms, it is widely used, primarily in news and media contexts, though leaning towards the informal side. While acceptable in many situations, remember to consider your audience and the overall tone of your writing, and consider using alternatives like "that's right" or "indeed" in more formal settings. Be mindful of overuse to maintain a professional tone.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
that's right
Directly affirms the preceding statement.
that's correct
Indicates accuracy of the statement.
that's true
Acknowledges the validity of the statement.
indeed
Formal affirmation or agreement.
absolutely
Emphatic agreement.
exactly
Expresses precise agreement.
you're right
Acknowledges the correctness of someone's statement.
I agree
Expresses personal agreement.
that is the case
Formal acknowledgment of a situation.
so it is
A more emphatic, sometimes rhetorical, affirmation.
FAQs
How can I use "that is so" in a sentence?
"That is so" is typically used to express agreement or strong affirmation. For example, if someone says, "This plan will definitely work", you could respond, "That is so".
What are some alternatives to saying "that is so"?
Depending on the context, you can use alternatives like "that's right", "exactly", or "I agree".
Is "that is so" considered formal or informal?
"That is so" leans towards the informal side. In formal settings, consider using more precise or formal language such as "that is correct" or "indeed".
When is it appropriate to use "that is so" in conversation?
It's appropriate to use "that is so" when you want to express strong agreement or affirmation in a casual or informal setting. Reserve it for scenarios where a slightly less formal tone is acceptable.
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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
89%
Authority and reliability
4.5/5
Expert rating
Real-world application tested