be completely sure of

USAGE SUMMARY

The part of a sentence "be completely sure of" is perfectly correct and usable in written English.
You can use it whenever you want to emphasize that someone is very confident about something. For example: "Before you take the job, be completely sure of the salary and benefits you will receive."

✓ Grammatically correct

News & Media

Science

Wiki

Human-verified examples from authoritative sources

Exact Expressions

15 human-written examples

As we sat in a shanty in a village north of Beni, Kakule, recounting what had happened, could not be completely sure of the soldiers' reasons for cannibalism.

The New York Times - Magazine

Anyone who wants to be completely sure of their information – personal, political, historical – is faced with a huge number of sources willing to provide it.

The Guardian - Books

Then he'd not just died in his early 40s in the plague in a year no internet site could be completely sure of, he'd also literally disappeared off the face of history.

The Guardian - Books

In the midst of all the development industry's concerns of "do we really make any difference", the only thing they can be completely sure of influencing is the lives of the people they directly touch.

The Guardian

Not only are some of the published data inaccurate but even the best statistics are available only after a period of time; the forecaster is forever predicting the future when he cannot be completely sure of the present.

Britannica

Still, to be completely sure of a product like this, I felt it was important to go through the whole process…so I did.

TechCrunch

Human-verified similar examples from authoritative sources

Similar Expressions

45 human-written examples

"I've never been completely sure of my dating".

The New York Times - Magazine

But I truly did play his wife; all at once I am completely sure of this, for I have recalled an odd detail.

The New Yorker

It is the split between dishes that are completely sure of their purpose and the ones so overembellished it's unclear what the idea was meant to be.

The New York Times - Food

"The one thing I am completely sure of is that you cannot be infected with H.I.V. because the virus was never present in the manufacturing process," Dr. Graham said.

The New York Times - Health

As ever, the targets will be chosen by the professionals, people who, having examined the available intelligence and the risks involved, are completely sure of the logic that underpins the time-critical case for the killing and destruction.

Independent

Expert writing Tips

Best practice

Use "be completely sure of" to express a high degree of confidence in a fact, decision, or understanding. Ensure the context supports such certainty to avoid misleading the reader.

Common error

Avoid using "be completely sure of" when your knowledge is based on assumptions or incomplete data. Instead, use phrases that indicate a degree of uncertainty, such as "believe to be true" or "highly likely".

Linguistic Context

The phrase "be completely sure of" functions as a verb phrase expressing a state of certainty or strong conviction about something. Ludwig AI confirms its correct usage, reinforcing its role in conveying confidence or assurance.

Expression frequency: Uncommon

Frequent in

News & Media

30%

Science

27%

Wiki

18%

Less common in

Academia

8%

Encyclopedias

7%

Formal & Business

6%

Ludwig's WRAP-UP

In summary, "be completely sure of" is a grammatically correct and relatively common phrase used to express a strong sense of certainty or conviction. As Ludwig AI confirms, this phrase is suitable for various contexts, ranging from news and media to scientific and academic writing. While it conveys confidence, it's crucial to avoid overstating certainty without sufficient evidence. Alternative phrases such as "be absolutely certain of" or "have no doubt about" can be used to achieve similar effects, while it can be adapted to casual context using phrases such as "be positive about", or even "be dead certain about". Remember to choose the most appropriate phrasing based on the specific context and desired level of formality.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

be absolutely certain of

Implies a stronger degree of confidence compared to "completely sure".

be entirely convinced of

Focuses on the mental state of being persuaded or assured.

have no doubt about

Highlights the absence of uncertainty or hesitation.

be positive about

Suggests a confident and optimistic perspective.

be fully persuaded of

Emphasizes the act of being convinced through evidence or reasoning.

be confident in

Highlights a feeling of self-assurance or trust.

believe without reservation

Emphasizes an unqualified and unconditional belief.

be as certain as can be about

Expresses the maximum possible level of certainty.

be in no doubt as to

Similar to "have no doubt", but more formal.

be dead certain about

Informal expression implying absolute certainty.

FAQs

How can I rephrase "be completely sure of" to sound more formal?

For a more formal tone, you can use phrases like "be absolutely certain of", "be entirely convinced of", or "have no doubt about".

What's a more casual way to say "be completely sure of"?

In a casual setting, consider using phrases such as "be positive about", or even "be dead certain about".

When is it inappropriate to use "be completely sure of"?

Avoid using "be completely sure of" when you lack solid evidence or when there's a possibility of being mistaken. In such cases, phrases indicating uncertainty are more suitable.

Is there a significant difference between "be sure of" and "be completely sure of"?

Yes, "be completely sure of" emphasizes a higher degree of certainty compared to the more general "be sure of". The addition of "completely" amplifies the confidence being expressed.