I like to get non English natives to pronounce Worcestershire sauce 9/10 times its wrong, If I am feeling particularly evil, I would get them to pronounce the welsh word Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch 🙂 as i've seen people ask, it means St Mary's Church in the Hollow of the White Hazel near a Rapid Whirlpool and the Church of St. Tysilio near the Red Cave. of course here's how to pronounce it, llan-vire-pooll-guin-gill-go-ger-u-queern-drob-ooll-llandus-ilio-gogo-goch. but Welsh isn't widely learnt, I my self don't know any welsh.
In Polish is many hard words to say, for example "żółć", "Grzegorz Brzęczyszczykiewicz" etc. (Of course for forgeiners, but with a few words is also hard for Poles)
It's funny, the word is the same in French and almost the same in Spanish (without one "L") "Pusilánime".
I think one of the hardest words in Spanish is "institucionalización" but we do not have that neverending-one-sentence words that exists in German or Finnish languages.
