I have been watching Graham Norton interviews on YouTube and I came across one interview with Benedict Carlton Cumberbatch where he couldn't say the word Penguin correctly during his narration of a documentary.
Apologies for the Facebook link but it is the only shortened version I could find. You might have to turn the sound on because it defaults to 'Off'
https://www.facebook.com/BBCOne/vide...2374693449607/
So .. do you have a word you just can't pronounce correctly?