Conflicting advice

[tacuba]

I have two grammar books that give different advice about using the subjunctive after verbs of disbelief. One book says that the subjunctive must be used after "No creo que" if the subject changes in the subordinate clause. The other book says that the speaker has the option of using the indicative or subjunctive depending on the amount of certainty the speaker has about the situation.

No creo que Juan y Paco vayan a la fiesta.
(Speaker has doubt that Juan and Paco are not going to the party)

No creo que Juan y Paco van a la fiesta.
(Speaker is pretty sure Juan and Paco aren't going)

What are your impressions? Can the indicative be used after "No creo que", as one book states, or is the subjunctive obligatory, as stated in the other grammar?

[AngelicaDeAlquezar]

I vote for the subjunctive there again.

Although one says "creo que ellos no van a la fiesta" with simple present, "no creo que ellos vayan a la fiesta" needs the subjunctive.

[Rusty]

The way I see it (though I'm not a native) is if you are certain, then to your mind it is factual information and the indicative is used for that. So the textbook that allows for both indicative and subjunctive patterns after 'no creo' is correct.

[chileno]

I'm with Angélica.

[sosia]

with Angélica and Chileno
For me, only the first ist right, because the use of "no creo" usually is doubt. If you're sure, you must use "estoy seguro"
No creo que Juan y Paco vayan a la fiesta.
Dudo que Juan y Paco vayan a la fiesta
(Speaker has doubt that Juan and Paco are not going to the party)

No creo que Juan y Paco van a la fiesta.
Estoy seguro que Juan y Paco no van a la fiesta.
Sé que no van a la fiesta.
No van a la fiesta
(Speaker is pretty sure Juan and Paco aren't going)

But if you use "creo" in other context (as a sure belief) then you can use it.
Yo creo que el Apocalipsis vendrá (Dudo que el Apocalipsis venga)

Saludos

[Rusty]

I'll recant and go with what the native speakers have said. My apologies.

[AngelicaDeAlquezar]

@Rusty: I don't think you have to apologize... it's been considered correct by some grammar books for what we see, but maybe that's a formula current Spanish has neglected.

[chileno]

Originally Posted by Rusty

I'll recant and go with what the native speakers have said. My apologies.

Again, I'm with Angélica.

[sosia]

I'm too. Strictly speaking, you're right Rusty, but nobody uses it.
Saludos

[irmamar]

You can use "no creer" + indicative in questions:

¿No crees que Juan y Paco van a la fiesta?