A mio fratello piace la birra.
I cannot find any discussion of why the A appears above. Can anyone help with an explanation of when to use it?
This would be better answered by our friends in the Italian forum. Click edit, and use the drop down menu to select the Italian forum. Now save and see if you can get an answer.
I am a novice in Italian but I should imagine it is like in French. What we are actually writing in "a mio fratello piace la birra" is not a word for word translation of my brother likes beer but literally "beer is pleasing to my brother" mio fratello must be an indirect object (if you understand grammatical terms) and therefore will need the preposition "a"