Hi, you have a good question, cause commonly you see both cases. But, refering the examples you want to know, in the grammar's rules says that: - Countries and other places (like states, cities) .. Brasil, América, Lisboa.. are capitalized.* - Days, months and season.. sábado, fevereiro, verão.. aren't capitalized.** - And concerning languages and studies, both cases are correct... inglês ou Inglês, matemática ou Matématica. I hope this is helpful ;)

Yes, they are! The Portuguese capitalization rules are pretty much similar to the English ones. Countries, cities, people's names, streets, languages, days/months, so on.