It is always necessary early on in the learning process to have a thorough understanding of the aria’s text. There are many translations freely available online, for example http://www.theariadatabase.com, as well as books of translations .
It is recommended to consult several different sources of translations, including checking particularly important words from a dictionary for a fuller understanding of their usage and etymology. For example, in English, the words ‘beautiful’ and ‘pretty’ are fairly synonymous, and yet they have subtle differences between them. The use of a particular key words in an aria is worth investigating in depth as it can lead to a nuanced understanding of the character’s thoughts and emotions.
Much as been written elsewhere on this subject. This approach would be the same for both the opera and for a concert.
 Books such as: Richard Colwell and Peter R. Webster, MENC Handbook of Research on Music Learning: Volume 1: Strategies, (OUP USA 2011).
. This approach would be the same for both the opera and for a concert.