My real block is - American surnames. I never know, when it looks like a European name, if it's going to be different! E.g Wagner....is it Wagg-ner or Varg-ner?
Eggplant, but we also have flipping words like yoghurt and hummus that I get lost on with the spelling changing. Think hummus use to br spelt hummous...am I going totally barmy with this one?