Not really vs Perhaps not

When to use each in English, with meaning, register, and examples.

Not really

InformalTop 2,000 (common)

Perhaps not

Top 2,000 (common)
Most formal: Perhaps not
 Not reallyPerhaps not
Pronunciation🇬🇧 //nɒt ˈrɪəli//🇺🇸 //nɑt ˈrɪəli//🇬🇧 //pəˈhæps nɒt//🇺🇸 //pərˈhæps nɑt//
MeaningNot true or correct.Maybe not
ExampleWhen he said he was an expert, I thought, 'Not really'.I thought about joining the team, but **perhaps not**.
RegisterInformalNeutral
How commonTop 2,000 (common)Top 2,000 (common)
Collocationsnot really my thing, not really sure, not really interestedsuggest that perhaps not, feel that perhaps not, think that perhaps not
Common mistakesUsing it in very formal writing or speeches., Confusing with 'not really' as a definitive answer instead of an expression of doubt.Using in overly formal contexts., Confusing with 'maybe' which is less definite., Assuming it expresses strong disagreement.
Usage notesUsed to express disagreement or doubt. Common in casual conversations, but may be too informal for formal settings.Used to express uncertainty about a situation or idea. More polite than simply saying 'no'.

See it in real clips

Not really
Perhaps not

Frequently asked questions: Not really vs Perhaps not

What's the difference between Not really and Perhaps not?

Not really: Not true or correct. Perhaps not: Maybe not

Which is more formal: Not really and Perhaps not?

Perhaps not is the most formal of these.

Can you show an example of each?

Not really: When he said he was an expert, I thought, 'Not really'. Perhaps not: I thought about joining the team, but **perhaps not**.

Can I use Not really and Perhaps not interchangeably?

Not always. Not really and Perhaps not are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.