Interesting (to me) facts about Portuguese

The name of the city I'm in, Recife, means "reef" in Portuguese, and there are dark stony reefs in the ocean that show at low tide from my hotel window—you can see the reef in the photo. They stretch along parts of this area of the coast. It is apparently safe to go swimming inside the reef, but not outside, and not in areas where there are no reefs, because of the danger of shark attacks. Along the beach, there are signs at regular intervals warning about this, with the words "perigo," danger, and "tubarão," which I infer to mean shark. This is interesting because the other city in Brazil I'll be visiting later, where the genre conference is being held in August, is the city of Tubarão.

Finally, I learned that the Japanese word for thank you, "arigato," which I learned when I was in Japan in June, is derived from the Portuguese for thank you, "obrigado/a" (as in obliged, with the common l–r substitution that Portuguese makes from other Romance languages). Apparently this word was adopted from the Portuguese explorers of the 16th century because the Japanese had no word for thank you.

Time to listen to my next lesson in conversational Portuguese.