Disagreement between adjective and noun in Brazilian Portuguese

Even though Portuguese requires that adjectives agree with the nouns they refer to, I have seen a few instances where some (many?) Brazilians don't follow that, as in É muito esquisito (sic) essa palavra(Is very weird this word* = This word is very weird.) As far as I have been able to observe, this mainly happens when adjectives are placed before nouns in the predicate position. This concurs with other instances of nonstandard usage, as placing a plural subject after a singular verb (Veio todas as pessoa(s)* - Came, sing., all person/people* = All people came.) One would think that somehow verbs and adjectives placed before their nouns or subjects would be in some sort of neuter form. This reminds me of German adjectives, which agree with nouns in the attributive position: Das ist ein neues Haus. (This is a new house), but remain unchanged in the predicative position: Das Haus ist neu. (This house is new)