Mother Tongues
slavenorth.com
slavenorth.com
A few from English that I like:
curglaff - the shock felt in bathing when one first plunges into the cold water
groak - to silently watch someone while they are eating, hoping to be invited to join them
The 'ы' in Russian is tough for English speakers even to say (at least, it has seemed so when I've seen people try to say it for the first time!), and we just don't have a letter that represents that sound.
Similarly, Arabic has several sounds that have no equivalent in English, so you see words with 3s in them (like 'na3m')--the 3 stands in for a ع (aiyn), which we just have no sound for.
But impossible? Nah. People can understand what you mean.
I on the other hand can't hear the difference between Hindi "b", "v", "g", and "k" half the time :)