Falsos Cognatos: Sympathetic

I have always found "simpático" to be a word that doesn't translate quite that well into English. I'd be glad to have someone prove me wrong. In the meantime, "nice" and its corresponding noun "niceness" seem like apt candidates.

She's a really nice person. [Ela é uma pessoa muito simpática].

Don't let her niceness fool you. [Não deixe a simpatia dela te enganar].

Alternative options include the casual, mildly colloquial, Spanish-derived "simpatico", which made its way into English at some point in the relatively recent past and doesn't seem in too much of a hurry to leave. The word, of course, has retained its original Spanish sense of "likeable" and "agreeable".

"Someone who is simpatico is pleasant and easy to like." (Longman Dictionary of Contemporary English)