The main language spoken in this area is Portuguese. Many people also spoke English, and we were able to speak Spanish with some people.
The euro is also used in Portugal. We didn't have to change our money over once we crossed the border, because we never left the European Union.
A bottle of water costs about 1.50€. Porto is a rather touristy city, so we expected to see some higher prices than in our small city in Spain.
The best meal of the week had to be this amazing sandwich meal called Francesinha. It's a meaty sandwich with three pieces of bread, a heavy orange sauce, cheese, an egg and French fries. It's very big, so I suggest either trying it when you are very hungry or sharing it with others.
We listened to a lot of Portuguese music while we were in Porto, but we also heard a lot of American pop music. While we were driving, we really enjoyed listening to classical music on the radio.