I don't think so

USAGE SUMMARY

The phrase "I don't think so" is correct and can be used in written English.
It can be used to express doubt or disagreement. For example: "Do you think I should wear a suit to the interview? I don't think so."

✓ Grammatically correct

News & Media

Academia

Science

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

i don't think so.

University of California, Berkeley

I don't think so whatsoever.

The New York Times

HUNSTMAN: I don't think so.

The New York Times

C.J.: I don't think so.

The New York Times - Magazine

Happily, I don't think so.

The New York Times

I don't think so personally".

Independent

"I don't think so, Wally".

The New Yorker

Or I don't think so.

The New Yorker

So I don't think so.

The New Yorker

"I don't think so, Cal".

The New Yorker

I don't think so, frankly".

The New York Times

Expert writing Tips

Best practice

Use “I don't think so” to express disagreement or doubt politely. It's less confrontational than a direct 'no'.

Common error

Avoid using “I don't think so” repeatedly in a conversation; vary your responses with alternatives such as "I doubt it" or "I'm not so sure" to maintain engagement and avoid sounding monotonous.

Linguistic Context

The phrase “I don't think so” functions as a polite form of disagreement or contradiction. It softens the impact of a direct negative response. According to Ludwig AI, it's grammatically correct and widely used.

Expression frequency: Very common

Frequent in

News & Media

69%

Academia

12%

Science

19%

Less common in

Formal & Business

0%

Encyclopedias

0%

Wiki

0%

Ludwig's WRAP-UP

The phrase “I don't think so” is a common and grammatically correct way to express doubt, disagreement, or skepticism. According to Ludwig AI, it is suitable for use in written English and particularly effective when a polite yet clear expression of a differing viewpoint is required. The phrase is versatile, appearing frequently in News & Media, Academia and Science, as well as authoritative sources such as The New York Times and The New Yorker. Although commonly used, it is advised to avoid over-repetition and instead vary responses with alternatives like “"I doubt it"” or “"I don't believe so"”.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

I don't believe so

Expresses a lack of belief rather than a disagreement. Has a similar meaning but focuses on personal conviction.

I doubt it

A more concise way to express doubt. Suitable for informal settings.

I disagree

A direct expression of disagreement. More assertive than the original phrase.

That's not likely

Indicates a low probability of something happening. Less personal than the original.

I'm not sure about that

Expresses uncertainty or skepticism. More hesitant than the original.

I wouldn't bet on it

Suggests a strong disbelief in the likelihood of something. More colloquial.

Not in my opinion

Indicates disagreement based on personal judgment. Emphasizes a personal perspective.

I have my doubts

Expresses reservations or uncertainties. More subtle than a direct disagreement.

I'm skeptical

Indicates a tendency to doubt or question claims. More formal.

That seems unlikely

Suggests a low probability based on available information. Less direct.

FAQs

How to use “I don't think so” in a sentence?

Use "I don't think so" to politely express disagreement or doubt, such as in response to a suggestion or statement. For example, "Do you think it will rain today? I don't think so."

What can I say instead of “I don't think so”?

You can use alternatives like “"I don't believe so"”, “"I doubt it"”, or “"I disagree"” depending on the context.

Which is correct, “I don't think so” or “I think not”?

Both phrases are grammatically valid, but “I don't think so” is far more common in contemporary English. "I think not" can sound somewhat formal or old-fashioned.

What's the difference between “I don't think so” and “I don't believe it”?

“I don't think so” typically expresses disagreement or doubt about a statement or suggestion. “I don't believe it” expresses disbelief in something that has been said or presented as fact. The former questions an opinion, while the latter challenges truthfulness.