What's the difference between la opera and la obra? Aren't they the same thing? They mean "the work" correct?
Should't be "El opera" since opera begins with a vowel? when does that rule being applied and when not?
The rule is: Feminine nouns that begin with a stressed "a" use "el" as the singular article and "las" as the plural article.
Agua, águila, arca, all have stress on the initial a and us "el" as the singular article. (This includes words that begin with "ha", el hambe, las hambres).
Where as feminine nouns start with an unstressd "a" retain the use of "la" as the singular article. ex: la abeja, la actualidad, la agonía, etc.
Libra: Only certain words that begin with "a", not all vowels. For instance all of these words are feminine, but we use "el" in front of them: el agua (the water), el águila (the eagle), el arca (the ark), el hambre (hunger), el hampa (the underworld),(begins with the sound of "a"), el arpa (the harp)