Are there any words you find impossible to pronounce?

Benedict Cumberbatch cannot pronounce penguins.

Not me, but I had a Chinese complex analysis professor back in uni and the word "corollary" was her nemesis. She'd pause a tiny bit before starting, and then clamber over it like a rock climber and was visibly relieved to have made it to the other side in one piece. Poor lady, "corollary" was used like a million times in that class.

Ibuprofen

Veterinarian. That's not a word that rolls off my tongue very easily. I end up stuttering when I try to say it and when I finally manage to say it without stuttering, it ends up sounding more like veteritanian.

Quite a few in Dutch, like rigening, rijbewijs, vreemdelingspolitie, brug, Oegstgeest

I can't ever say ammonia or salmon correctly. People make fun of me for it.

@NorthenRoses So What Do You Think Of Sendhil Ramamurthy & Would You Do Him

Yup, and it's a German word: übrigens.

Some Japanese words. Like, Zen'in.