I think they can but it's kinda hard if they put the slang words in conversation, just imagine like the UK, US, Aussie, New Zealand people how they talk to each other.

Yes, the accent is quite different but we are able to understand each other in general.

Yes we can, but there are some vocabulary differences. Most of the time we can guess what the word means by analysing the sentence context. Here are some examples: Bus stop PT-BR: Parada/ponto de ônibus PT-PT: Paragem de autocarro Bathroom PT-BR: Banheiro PT-PT: Casa de banho Juice PT-BR: Suco PT-PT: Sumo Cellphone/Mobile PT-BR: Celular PT-PT: Telemóvel

There are ten light dialects in Portugal and 16 in Brazil. It is then not easy to answer your question. https://en.wikipedia.org/wiki/Portuguese_dialects

Olá, meu nome é Argos Rocha e eu sou brasileiro. Então, nós entendemos os portugueses de Portugal sim, entretanto, ainda há umas palavras que nós pedimos para o outro falar novamente ! Translate for the English .... Hi, my name is Argos Rocha and I'm brazilian. Then, we understand the portugueses yes, but, there are some words which we asked for the other to speak again !