I can not say about BP, since I've had so many surprises here already, but in EP, the "a" should be "à". "Responder" usually requires a "complemento indirecto", which is introduced by the preposition "a". If a noun follows, it usually brings a definite article with it and this contracts with the preposition. For example, "responder ao repto lançado pelo adversário". Where the noun is feminine, the contraction is "a+a = à". It is very very common in Portuguese. For example, "ele atirou-se à água".
The point is not whether we respond to something or to someone. I may be responding something to someone or to something. For example, "responder «sim» ao desafio proposto". "O desafio" is an indirect complement, "sim" is the direct complement, but none of them is a "someone".
I just stated the reason why in Brazil we add no crase in this sentence ;)
Ok, but now I am curious. Is it also "Responder o anúncio" in BP? Or "Responder ao anúncio"?
[To Paulo Henrique below:]
I had no idea you could say that in BP. Always learning. :)
That's what I always say! Also for my own language, not only for PT-PT =)
Even the English grammar puzzles me. Can means able to. Consegui is the past conjugation of can? Can could also be present tense? Could you translate this as "I used to be able to answer the question"?
Hi, many questions here. "Consegui" is the past of "Conseguir", and it points to a definite point in time. So, "I used to be able to answer the question" seems wrong, because of a sense of continuity.
I don't think "could" has any sense of present tense, although it does have a sort of conditional sense: "I could do that for you, if...."
Another good translation here is "I was able to answer the question", which I think is what you were hinting at.
I usually think of could in the present tense ie I'm able to now, but I might not. That's the first meaning I think of. But it can also mean I used to be able to, but can no longer. For me was able and used to be able can mean the same thing. But was able can also mean at the time, rather than used to be able that only means can no longer. So your last sentence seems the best translation to me, although whether DL accepts it is another thing. I hope that it's a bit clearer for foreign learners of English than it is for me, ha.
Wouldn't could (past tense of can) normally be translated as a form of the verb poder?
I think that conseguir often means obtain or get, but perhaps with an infinitive it means something like "managed to ..." or "succeeded in." Your translation seems better than "could" as it could mean too many different things, which is difficult when you are trying to understand new vocabulary. (Able to answer is accepted)