¿Es imposible subjuntivo o es subjuntivo imposible?

Question

I have been learning the subjunctive mood and I mostly understand it. When the main clause indicates certainty, the indicative is used in the subordinate clause. Por ejemplo, “Sé que este es mi libro.” (I know that is my book.) When a main clause shows some uncertainty, the subjunctive must be used. Por ejemplo, “Es posible (o dudo) que este es mi libro.” It is possible (or I doubt) that this is my book. There is a fairly long list of main clauses that indicate use of the subjunctive in the subordinate clause. Usually included is such a list is “es imposible que”. In English this phrase (it is impossible that) would seem to be a statement of certainty - negative certainty but still certainty. Can someone explain the nuances of “es imposible que” in spanish that require el subjuntivo with this phrase?

Answer 1

There are three ways of using the verb "ser" (at least this is what my logic circuits' professor told us)

The first one (imperative) works by declaring or defining the condition of a thing: "sea x igual a 5" (be x equal to 5). This way is similar to christening "x" with the name "5". It will not change. This isn't very much used (except by kings, I think)

The second one (indicative) defines some condition in the present (but it does not tell you anything about the past or present) "x es igual a 5" (x is equal to five) (for now, at least)

The third one (the subjuntive) works with a possibility, and needs another clause. "si z es igual a 4; que x sea igual a 5" "if z is equal to 4, x equals 5"

The sentence "es imposible que ese sea mi libro" it's in subjuntive because you're not defining it as "not your book", ("ese no es mi libro","ese no sea mi libro"), you're assesing your owning it as "imposible". The certanity exist, but you're still assessing it, so it's a subjuntive.

If you know programming, the first way is x=5, the second is x==5 and the third one is "if y==4; x=5; "

Thanks for proving my point!! lol - gsdfsggs, Nov 10, 2012

Hmm, yes, quite. >_> - cola_jet_set, Nov 11, 2012

Answer 2

Querés decir "Es posible que este sea mi libro"?

I don't have an answer but in my experience it a lot easier to learn subjunctive in context, specifically in the context of the main clauses that indicate subjunctive.

For me, it was just easier to think "Oh, I use "sea" instead of "es" after "es necesario que" instead of trying to measure language nuances or "cultural differences", which are really difficult to measure or analyse.

Thats just my 2 cents.

I agree, it would take forever and you would never ever be able to open your mouth again. Best just take some common forms as seen. - annierats, Nov 10, 2012