"Please, I need a lot of water."
Translation:Por favor, yo necesito mucha agua.
Duo does a great job introducing exceptions. If a noun begins with "a", is feminine AND the emphasis is on the first syllable, as in "agua", then the singular article changes for easier pronunciation. Therefore, "el agua". If the noun begins with"a", is feminine AND the emphasis is NOT on the first syllable, as in "amiga", then the singular article stays "la". Therefore, "la amiga". I hope this helps.
This little article was very helpful to me in understanding why el agua is used when agua is indeed femine. There are other feminine nouns that take el before. The article explains it very well.
it's actually femenine, but as it starts in a, you put 'el' to make it sound better cause if not it would be 'laagua'. but in plural it is las aguas. This hapens with other words too, el hacha and las hachas. But i don't know why it is la amiga and not el amiga. i think because amiga is always a girl and you can't change the preposition.
Agua is actually femenine, but when a noun starts in a, you put the masculine article (only when singular). El hacha, las hachas (the axe, the axes). El agua, las aguas (the water, the waters) But this rule doesn't go with people, for example, la amiga, the friend (femenine).