I'm not really sure

USAGE SUMMARY

"I'm not really sure" is correct and can be used in written English
You can use it when you are uncertain about something and don't have a definite answer. For example, "I'm not really sure when our next meeting is scheduled for."

✓ Grammatically correct

News & Media

Human-verified examples from authoritative sources

Exact Expressions

59 human-written examples

And I'm not really sure.

The New York Times

I'm not really sure why.

The Guardian

But I'm not really sure".

The Guardian - Sport

"I'm not really sure why I started.

The Economist

I'm not really sure what this means.

The Economist

"I'm not really sure why," he said.

The New York Times

"I'm not really sure, to be honest.

Independent

I'm not really sure what that means.

The New York Times - Sports

I'm not really sure about that.

The Guardian - Music

"I'm not really sure," she answered.

The New York Times - Magazine

I'm not really sure what art is".

The Guardian - Arts

Expert writing Tips

Best practice

When writing formal texts, think of rephrasing "I'm not really sure" to a more suitable and professional expression, like "I am not entirely certain".

Common error

While acceptable in casual settings, avoid using "I'm not really sure" in formal writing or presentations. Opt for more professional alternatives like "I am uncertain" or "I do not have sufficient information at this time".

Linguistic Context

The phrase "I'm not really sure" functions as a hedge, softening the expression of uncertainty. According to Ludwig, it is considered grammatically correct. It serves to express a lack of definite knowledge or confidence in a statement.

Expression frequency: Very common

Frequent in

News & Media

87%

Science

7%

Wiki

2%

Less common in

Encyclopedias

0%

Formal & Business

0%

Social Media

0%

Ludwig's WRAP-UP

In summary, "I'm not really sure" is a common and grammatically correct phrase used to express uncertainty or a lack of knowledge. As Ludwig AI confirms, it's suitable for everyday conversation and informal writing, but should be replaced with more formal alternatives in professional or academic contexts. Its frequency in news and media highlights its role in conveying a degree of doubt or speculation. When seeking alternative expressions, consider phrases like "I'm not entirely certain" or "I don't know for sure" to adjust the level of formality.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

I'm not entirely certain

Replaces "really sure" with "entirely certain", suggesting a slightly more formal tone.

I'm not completely sure

Substitutes "really" with "completely", offering a similar level of uncertainty with a slightly different emphasis.

I'm not quite sure

Uses "quite" instead of "really", conveying a slightly softer or less direct sense of uncertainty.

I'm uncertain

Shortened version omitting "really", offering a more direct and concise expression of uncertainty.

I'm unsure

Replaces "not really sure" with "unsure", resulting in a more concise and informal expression.

I don't know for sure

Shifts the sentence structure to focus on the lack of definite knowledge.

I couldn't say for sure

Emphasizes the inability to provide a definitive answer due to lack of knowledge or certainty.

I have my doubts

Expresses uncertainty through the presence of doubts, implying a level of skepticism.

I'm a bit skeptical

Introduces the idea of skepticism rather than direct uncertainty.

It's hard to say

Indicates that a definitive answer is difficult to provide, rather than expressing personal uncertainty.

FAQs

What does "I'm not really sure" mean?

The phrase "I'm not really sure" expresses a lack of certainty or knowledge about something. It's a common way to admit you don't have a definite answer.

How can I use "I'm not really sure" in a sentence?

You can use "I'm not really sure" when responding to a question you don't know the answer to, for example, "I'm not really sure what time the meeting starts".

What can I say instead of "I'm not really sure"?

You can use alternatives like "I'm not entirely certain", "I'm unsure", or "I don't know for sure depending on the context.

When is it inappropriate to use "I'm not really sure"?

Avoid using "I'm not really sure" in formal settings such as academic papers or professional presentations. In such cases, more formal alternatives like "I am uncertain" or "I do not have sufficient information" are more suitable.