Hey ericnosborn! Sour and bitter are two different tastes (azedo and amargo), and I imagine they are after the closest translation in relation to the original sentence. Although we are more likely to call a pineapple sour, the sentence does not give that quality to the fruit... (a pineapple is just as likely to be sweet, too -- but this particular one isn't... it's bitter). I hope it helps! =D
Hey danmoller! Although a (bad) pineapple could be bitter, remember that many duolingo sentences do not reflect reality. The literal meanings of the sentences are not important... I believe their objective is to teach different words to you, even if these word happen to be together in a nonsense sentence ("the happy pineapple is blue!" -- gramatically correct, but unlikely). All of this is done to increase your general vocabulary so that you can build your own sentences correctly later. =)
I guess my question was more that Duo listed "bitter" and "sour" as possible translations for amargo, and did take it to mean sour when being used to describe milk. Is that just a difference in idiom when describing milk that has gone bad, a mistake on Duolingo, or can amargo sometimes mean sour?
Hey, ericnosborn! That seems to be Duolingo's mistake.
Amargo always means bitter (the only half-exception I can think of is that we use it to describe dark chocolate -- for example, the "semi-sweet chocolate" used in cooking is called "chocolate meio-amargo" in BR PT... but that is just a case of us focusing on the bitterness as opposed to the lack of sweetness!).
Azedo is always sour. We use it (often) to refer to milk that has gone bad, in fact:
O leite está azedo -- The milk is sour
O leite azedou -- The milk went sour (the milk has gone bad)
Coloque o leite na geladeira para não azedar -- Put the milk in the fridge so it doesn't go sour/bad.
So Duolingo should not have offered amargo as a translation of "sour". Only if the milk was truly bitter. I hope it helps! =)
The explanation I would have for "ser" is that is is an inherent characteristic of the pineapple, even if temporary. In Spanish (and I assume Portuguese is similar, I'm still a beginner) ser is always used for traits and colors and characteristics, even if they might be temporary. There are a few exceptions, but in this case, even without context, it is a characteristic. Also, the verb estar has not been introduced up to this point in the tree.
Frustrated that Duolingo mixes Brazillian and European Portuguese, which are more often that not regarded as two language types. Can anyone recommend a program which focucuses on Europen Portuguese only. Don't want to waste time learning stuff that won't work where I live.