For me it's mainly two things.
The constant use of the i: I think, I want, etc. In italian the I is not used, and when I'm (grrr) writing in english it feels like I want to say I I I like a donkey or that prisoner TV show. Horrible.
The word "simpatico". comes from the greek, means roughly with-feeling (sun-pathos). We use it here a lot to mean a carefree, easy-going personality, but in a friendly way,meaning also "I like him/her/it", or "it's nice, light, I'd like to spend some time talking to/about him/her/etc." Nice is too detached as a meaning for translating simpatico.
