ATTENTION: Brazilians do not speak Spanish. And most of us do take offense at this confusion, however innocent it may be.

Brazilian Portuguese is a variation of Portuguese used in (duh!) Brazil. Although the language derived from Portuguese of Portugal, it is now different enough to impair communications between Brazilians and Portuguese people.

It's not as similar as UK and US English:
One has to speak very slowly to be understood by the other. Some times it's even impossible to understand due to different use of words and slang. To prove it, you just have to ask the huge number of jokes Brazilians make using what the Portuguese consider "normal" words - but mean quite obscene things in the Brazilian version. The opposite is, of course, true.

Maybe the the most marked difference between the languages is the Brazilian’s craze for verbs in gerund and Portugal’s hatred of such abuse.

As if classical Portuguese was not complex enough, Brazilian Portuguese is not spoken nor written in the same fashion in all parts of my big country. All regions have their own accent, slang and influence. For instance, the northen folk have a lot of native indian influence and that is very clear in their speech. We cariocas have the magic power to make most consonants sound like 'schhhhhhhhhhhhhh', hissing a little bit.

Brazil was the biggest Portuguese colony until the 19th century and our major influences came from Portugal. But we also had invasions (and consequent mixing of blood and cultures) from the French, the Dutch, and loads of immigrants from Japan, Italy, Germany and most northern European countries. We had thousands of indian tribes when the Portuguese arrived, but they were quickly killed by white-men's diseases, slavery and plain old massacre.