EL agua or LA agua
I was doing a practice quiz with direct pronouns, and "el agua" showed. It was multiple choice and i picked "lo" because "el" is masculine. The answer was wrong and said "el agua" corresponds with the feminine direct object "la". Is this an error on the site's part, or is "el agua" a masculine word with a feminine DOP? If it is not a site error, can someone explain this to me?
3 Answers
Agua, alma, arte and similar words are feminine. In singular, they use "el" because grammar rules dictate that a word with stress over the first letter of a word that is "a" must use "la" for proper pronunciation.
Pronouncing the same vowels together creates an effect called cacophony (harsh or discordant sound). To avoid that, feminine words such as agua (whose stress falls on the first a of the word) change their article in the singular from la to el. Some words that start with ha (the h at the beginning of a word is silent in Spanish) also change their article to el to avoid the harsh sound.
Examples:
El alba (the dawn)
el arca (the ark)
el hambre (hunger)
el hampa (the underworld)
el arpa (the harp)
el águila (the eagle)
It is LA agua, but Spanish speakers us 'el' instead of 'la' in front of words beginning with a stressed 'a'. Ostensibly to keep them from running together, even though they do that with pretty much all words 
hth roger
p.s. this also applies to words starting with ha since the h is not pronounced
