As you know, the subjunctive is a “mood” rather than a tense. It is an attitude that the speaker has toward a fact or action, in which the outcome is not certain. It represents hypothetical situations or contingency. Whereas with the indicative, we had fact and certainty, with the subjunctive we don’t.
In this section, we will learn how the subjunctive is used to express doubt, denial and disbelief.
DOUBT
When the verb of the main clause expresses uncertainty or doubt, the verb in the subordinate clause is in the subjunctive.
I doubt that I can be there at that time.
Dudo que yo pueda estar ahí a esa hora.
***If there is no doubt, the speaker uses the indicative...Estoy seguro (a), no dudo, yo sé...***
I'm sure that I can be there at that time. Estoy segura que yo puedo estar ahí a esa hora.
DENIAL
When the main clause denies or negates what is expressed in the subordinate clause, the subjunctive is used.
Ana denies that Carlos is her boyfriend.
Ana niega que Claros sea su novio.
***If there is no denial, then the indicative is used. ***
It's true that Carlos is Ana's boyfriend.
Es verdad que Carlos es el novio de Ana.
DISBELIEF
The verb "creer" is followed by the subjunctive in negative sentences, where it expresses disbelief.
No, I don't think she's going today.
No, no creo que ella vaya hoy.
***Creer is followed by the indicative in positive, affirmative sentences, where it expresses belief. ***
I think that he's going to leave today.
Creo que él va a salir hoy.
Indicative: Belief/Certainty
creer - to believe
no dudar - to NOT doubt
estar seguro - to be sure
no negar - to NOT deny
pensar - to think
es claro - it is clear
es cierto - it is certain
es evidente - it is evident
es indudable - it is without doubt
es seguro - it is sure, certain
es verdad - it is true
Subjunctive: Disbelief/doubt
no creer
dudar
no estar seguro
negar
no pensar
no es claro
no es cierto
no es evidente
no es indudable
no es seguro
no es verdad
Tal vez and quizás, meaning perhaps or maybe, are followed by the subjunctive to express doubt or uncertainty.
Maybe I will graduate next year.
Tal vez me gradúe el año próximo.
Maybe I will call you.
Quizás te llame por teléfono.
