Brazilians refer to their North American brethren by the demonyms canadense and estado-unidense (or estadunidense) – the latter in no small part as a way to assert the independence of the identity of America the continent vs. the United States.
Far removed from this specific linguistic power play, European Portuguese still hews close to English and prefers the term americano/a in reference to people or subjects related to the United States of America.
Sometimes, norte-americano/a is used as a relative compromise (one that ignores only Canada and/or Mexico instead of the whole American continent, that is), but the principle of least effort usually brings it back down to americano/a (it’s probably for the same reason that the common yet cumbersome forms used in BP haven’t gained traction over here).
Since adjectives are usually inserted in a broad context (having at least a noun they refer to around), it shouldn’t be hard to understand if americano/a is being used in reference to the country or the entire continent; take note of authors who go out of their way not to use (or solely use) this term, since that’s usually a conscious effort to criticize the way this word is used for political purposes (vd. first paragraph above).
Related words/useful sentences:
- [o] Tio Sam: Uncle Sam
- [os] Grandes Lagos: Great Lakes
- [as] Montanhas Rochosas: Rocky Mountains
- [o] Congresso: Congress
- [o] Senado: Senate
- [a] Câmara dos Representantes: House of Representatives
- [o] Presidente: President
- Barack Obama é o atual Presidente americano. Barack Obama is the current President of the United States.
- As eleições para o Congresso americano ocorrem a cada dois anos/de dois em dois anos. The elections to Congress take place every two years.