Translation:The politician is not talking to the English people, but to the Brazilians.
Certain adjectives in English can be used with "the" but with no noun to mean a general class of people (the elderly = elderly people; the blind = blind people; the poor = poor people etc. etc.)
For some reason, nationality adjectives ending -sh, -ch, or -ese can be used this way (the English = English people; the French = French people; the Japanese = Japanese people). However, nationality adjectives ending -an cannot be used this way. Instead you use a nationality noun in the plural (Brazilians, Americans, Iranians etc. etc.)
There's nothing incorrect or even informal about it, it's just one of those littke quirks of English grammar that native speakers do naturally, and no one remembers to tell foreign language learners. (I am an English teacher, by the way!)
Actually, you can use it with the -an nationalities, but primarily in a comparative sense:
"Due to their different languages and dialects, the customs agents were assigned to translate for the 3 groups of South American tourists: the first for the Columbians, the second for the Brazilians, and the third for the Peruvians."
@Steven, that was sheepishangel's point -- you can say the English, the Japanese and use these adjectives as collective nouns, without having to change the adjectives at all. However, with the -an adjectives, you need to add the plural -s on the end to use them this way: exactly as in your examples. :)
No, in the plural, but adjectives do not inflect in English, and English here works grammatically like an adjective (but Brazilian does not, though it can also be an adjective).
French, Spanish, Chinese, Japanese are like English, but German, Russian, Italian like Brazilian. I suppose it has to do with the ending.