The word "americano" is the adjective for "American". http://dictionary.reverso.net/spanish-english/americano/forced http://dictionary.reverso.net/english-spanish/American http://dictionary.reverso.net/spanish-english/estadounidense
In English, 'Spanish', 'American', 'Cuban', and other words for nationalities as well as languages are capitalized.
In Spanish, 'español,' 'americano', 'cubano' and other words for nationalities as well as languages are not capitalized.
It simply depends on the conventions of the particular language. Does that answer your question?
In English, nationalities are usually adjectives:
He is Japanese
He is Irish
No English speaker would say an Irish. Some nationalities also can be nouns, like American or Italian.
He is Italian / He is an Italian
He is American / He is an American
Both American and an American work here, though the former is a more literal translation.
Es and Está is one verb in English (verb "to be")
You use "Está" when it's a location or a temporal condition: -Él está aquí (he is here) or Él está enfermo (he is sick)
You use Es when u want to say something specific and permanent about the subject:
-Él es alto (he is tall), él es blanco (he's white), él es Peter (he is Peter)
Hope this helps
In Canada, "American" always refers to someone from the US, North or South American refers to someone from those continents, northern or southern American refers to someone from the northern or southern parts of thd US. There is no word that refers to someone from either North or South America because "America" is not considered to be a continent (you might say "he's from the Americas" or "he's from the Western hemisphere"). I gather that this is different in Latin America in that "America" is the name of a continent there.