Never but never vs Under no circumstances

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

Never but never

Informal Beyond 10,000 (less common)

Under no circumstances

	Never but never	Under no circumstances
Pronunciation	🇬🇧 //ˈnɛvər bʌt ˈnɛvər// 🇺🇸 //ˈnɛvər bʌt ˈnɛvər//
Meaning	A strong phrase emphasizing 'never' more than once.
Example	I will never but never go back to that restaurant.	-
Register	Informal	-
How common	Beyond 10,000 (less common)	-
Collocations	never but never say, never but never do, never but never promise, never but never agree, never but never hope	-
Common mistakes	Using it in a formal context where it sounds too dramatic., Confusing it with 'never ever', which has a similar meaning but a different tone., Omitting the second 'never' which changes the emphasis.	-
Usage notes	Use in informal speech or writing to emphasize that something will not happen. Avoid in formal contexts.	-

See it in real clips

Agatha Christies Poirot › S1 E1

Never, but never must Chief Inspector Japp hear

Never but never

Avengers › Avengers Infinity War

Under no circumstances

Under no circumstances

Frequently asked questions: Never but never vs Under no circumstances

What's the difference between Never but never and Under no circumstances?

Never but never: A strong phrase emphasizing 'never' more than once. Under no circumstances:

Can I use Never but never and Under no circumstances interchangeably?

Not always. Never but never and Under no circumstances 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.