This is different from previous statements that have been "pleasing to" . A mio fratello piace la birra,. which would be ... to my brother is pleasing to the beer. They keep confusing us. If it is "to my brother the beer is pleasing", why would it not be la birra piace a mio fratello. . There seems so be some flip flopping of this, making it confusing.
"Piacere" is an intransitive verb. With Italian intransitive verbs, it is more natural for the subject to come after the verb. When expressing your personal preferences, you usually say "mi piace la birra", (to me the beer is pleasing), where the subject (la birra) comes after the verb.
For this sentence, "a mio fratello piace la birra", the literal translation is "to my brother the beer is pleasing." It is the preposition "a" that tells you to whom the beer is pleasing. Because there is no preposition before "la birra", we know it's the subject.
Yes there are usually multiple correct answers, but what I was talking about here might not be an accepted answer, it's just the literal translation.
The Italian means "beer is pleasing to my brother", which sounds strange in English, so we translate it as "my brother likes beer".
I don't see any difference to previous "someone likes something" sentences.
While this sentence means: "My brother likes beer",
try to think of it as the way Yoda from Star Wars speaks:
"To my brother, pleasing is the beer."
"A mio fratello, piace la birra."
It is the same structure as all of the piacere (pleasure \ to like) sentences in Duo up to this lesson.
You could also write this in the following order:
"La birra piace a mio fratello."
"The beer is pleasing to my brother." (pseudo-translation just to explain)
Both orderings are legitimate in Italian,
and translate to: "My brother likes beer."
That would also be "A mio fratello piace la birra". In French, Spanish, Italian you often have to use the definite article to signal "general reference" which requires the zero article in English):
I love cheese : Adoro il formaggio
I love the cheese (e.g the one from the market) ; Adoro il formaggio.
I love music - Amo la musica, etc.