I'm Brazilian and I need pay attention when I heard Portuguese people because they speak faster than Brazilians and the accent is different. Portuguese use the personal pronouns "tu" and "vós" and the Brazilians rarely use them (except in some regions). We use "você" and "vocês".  And some words are writen with small differences. This is what I remember in this moment. Bye.

Not too big. The accent is very different. Worst then british and american. But It use the same words. The portuguese from Portugal is more classic, like British English. I think in Brazil we have a lot of slangs more! But If you learn Portuguese from Brazil or Portugal, it´s just a question of accent to talk in both countries.

Sorry for my English!