From Portuguese:
Saudade: it is a noun that is akin to "missiness", the feeling of missing someone. A bit like "homesick", but that can be used not simply for missing home, but for when you miss someone, or something (anything).
Chato: similar to "pain in the neck", but a bit less strong. It is the opposite of nice, used when you don't really like someone (but that person does not necessarily have to be so unbearable as a "pain in the neck").
Frescura: close to "fussiness". It is even hard to explain, but it is used when someone is fussy about something, or particular about something, we say that the person "is with frescura".
este, esta, isto, esse, essa, isso, aquele, aquela, aquilo: similar to "this" and "that". Actually, "isto", "este" and "esta" can be translated exactly as "this" (losing only gender information). But each of other two forms, when translated to their closest approximation, "that", lose some meaning. When the thing in question is closer to the listener we use "isso", "esse" and "essa", while "aquilo", "aquele" and "aquela" mean the thing is away from both. It's funny how Portuguese has no neuter pronoun ("it") but it has neuter demonstratives ("isto", "isso", "aquilo").
Interesting that... I once read that our thoughts are limited by the language we speak, and I think this is so true!