Is that so?

USAGE SUMMARY

The phrase "Is that so?" is correct and usable in written English. You can use it to express skepticism or surprise in response to something someone has said. Example: "You won the lottery? Is that so?" Alternative expressions include "Really?" and "Is that true?"

✓ Grammatically correct

News & Media

Academia

Science

Human-verified examples from authoritative sources

Exact Expressions

55 human-written examples

Is that so awful?

The New Yorker

Is that so wrong?

The New York Times - Food

Is that so hard?

The New Yorker

Is that so?

The New York Times

Is that so difficult?

Independent

Is that so terrible?

The New York Times - Food

Human-verified similar examples from authoritative sources

Similar Expressions

5 human-written examples

Is that necessarily so?

University of California, Berkeley

Is that indeed so?

Biology Direct

Isn't that so?

The New York Times

Isn't that so true?

The New Yorker

Isn't that so often the case?

The New York Times

Expert writing Tips

Best practice

In written dialogue, use this phrase to convey a character's dry wit, skepticism or professional detachment.

Common error

Avoid using "Is that so?" as a rhetorical device in formal scientific or academic papers. Instead, use more precise phrases like "Is this finding accurate?" or "Is this hypothesis valid?" to maintain a professional tone.

Linguistic Context

The primary grammatical function of "Is that so?" is an interrogative idiom used to prompt for confirmation or express skepticism. As seen in the numerous examples from Ludwig, it acts as a response token that allows a listener to maintain engagement in a conversation. It effectively functions as a shortened version of "Is it true that it is so?".

Expression frequency: Common

Frequent in

News & Media

68%

Academia

22%

Formal & Business

10%

Less common in

Science

5%

Social Media

3%

Reference

2%

Ludwig's WRAP-UP

According to Ludwig AI and the extensive data provided, "Is that so?" is a robust and versatile interrogative tool. It strikes a balance between curiosity and skepticism, making it a staple in both journalistic reporting and literary dialogue. While it is grammatically correct and widely accepted, its power lies in its restraint; it allows the writer or speaker to question a premise without providing a definitive counter-argument. Whether used to express genuine surprise in a news interview or to serve as a rhetorical pivot in an academic discussion, "Is that so?" remains a highly effective way to signal engagement and critical thinking in modern English.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

Is that true?

Focuses directly on the factual validity of the previous statement

Really?

A more common and emotionally expressive way to show surprise or doubt

Is that the case?

More formal and analytic, often used in professional or academic contexts

Indeed?

Highly formal and can carry a tone of dry irony or polite interest

Is that a fact?

Adds a slightly more investigative or confrontational tone to the query

Are you sure?

Questions the speaker's certainty rather than just the statement itself

No kidding?

Very informal and used to express genuine surprise

Seriously?

Modern and informal, often used to signal disbelief or annoyance

You don't say?

An idiomatic expression that is often used sarcastically to mean something is obvious

Oh, is it?

A shorter, often more dismissive or casual variation

FAQs

How do I use "Is that so?" in a sentence?

It is typically used as a standalone follow-up question. For example: "The company reported record profits this year." "Is that so? I heard they were struggling."

What can I say instead of "Is that so?"?

You can use alternatives like "is that true", "really", or "is that the case" depending on the context.

Is "Is that so?" considered rude?

It is generally neutral, but the tone of voice matters. It can sound politely interested, genuinely skeptical or even sarcastically dismissive depending on the delivery.

What is the difference between "Is that so?" and "Really?"?

While both express surprise, "really" is more common and emotive, whereas "Is that so?" often sounds more formal, detached or even slightly skeptical.