If you’re at a performance at Lyric and most other major opera companies worldwide, there will be translations projected above the stage, allowing you to follow along during the performance, literally line by line. If you’re sitting at home just listening to a CD, you can follow along with the libretto (text). A great many complete operas on CD include the full libretto and translation. If there’s no libretto included with the CD, just Google the name of the opera with the word “translation” and you should be able to find what you need online — especially if it’s a comparatively well-known work. Most operas on DVD give you access to subtitles.