(1a) SP: "as folhas secas são colocadas na cesta para serem trituradas."
("the dry leaves are put in the basket to be ground")
I believe that prescriptive, mainstream Portuguese (MPT) says:
(1b) "as folhas secas são colocadas na cesta para ser trituradas."
But even SP speakers probably say "elas foram lá para fazer um serviço." rather than "para fazerem um serviço.", which makes their usage irregular. Maybe they only inflect when the stem is short, like 1 syllable long?
(2a) SP:
"- Para quê você comprou essa vara?"
"- Para mim pescar!"
("- What did you buy this pole for? - For me to fish!")
(2b) MPT:
"- para eu pescar!"
The pattern seems to be that SP speakers inflect in places where MPT doesn't.
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Btw, the SP usage would be more natural for English speakers.
I can't tell about other languages though. In Dutch, there is no personal construction as in (2): you would have to say "for fishing!". I think this is also the case in German. (is this related to
this phenomenon mentioned by
easwaran?). What about French, Spanish, and other languages?
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In what ways is the subjunctive similar to case-marking?