"se" keeps popping up and I don't know how to use it.

Question

La sal se ha disuelto en el agua.

Can you explain why "se" has to be there?

Answer 1

I agree with comunacho's answer, except for the fact that in "la sal se disuelve", the se does not mean that "the salt dissolves itself", but rather "the salt gets dissolved in the water"

The sentence with se doesn't clarify which is the agent that dissolves the salt. Rather, it focuses on what happens to salt. If we had to look for an agent, it's the water what dissolves the salt, not the salt which dissolves itself, and the sentence would change to "El agua disuelve la sal".

Se disuelve = it gets dissolved

Good solution. I was just thinking that it being reflexive might make grammatical sense, but did not make chemistry sense, since the water does the disolving. - rogspax, Dec 21, 2012

Mejor dicho, ¡imposible! - francobollo, Dec 21, 2012

Answer 2

La sal se ha disuelto en el agua.

Here "se" appears because "disolver" (to dissolve) is transitive, so it needs a subject and an object, a "doer" and "something to be done to".

"La sal disuelve" is incomplete, it needs something to be dissolved. Because it's the salt itself what is disolved, this sentence should be something like "La sal disuelve a si misma", but instead we use pronouns "La sal se disuelve".

The pronoun "se" brings back the action to the "doer" (or "doers"), it's similar to "to itself" "to themselves" "to eachother",etc.

There is not reflexivity here, it's a passive sentence. - cogumela, Dec 21, 2012

Answer 3

Cogumela, deberías escribir algo en el foro relacionado al uso del "se" como voz pasiva y "se" como reflexivo. El legado de otros expertos en gramática en este foro es muy largo, complicado y fastidioso. Me estoy refiriendo a las ponencias de Lazarus, que son un somnífero en su mayoría.

A ti se te dan muy bien las explicaciones concisas. Yo me atrevería, pero te apuesto a que me llevaría un mes explicarlo en forma eficaz. ¡Piénsatelo!