Apuntes 6-7 de febrero El subjuntivo y el indicativo con verbos de duda y certeza The subjunctive and indicative with verbs of doubt and certainty Dudo que mi hermano venga a la fiesta. I doubt that my brother is coming to the party. Creo que mi hermana viene a la fiesta. I believe that my sister is coming to the party.

When the verb or expression that is used in the main clause expresses doubt, disbelief, or denial, the verb in the subordinate clause is in the subjunctive. Here is a list of some common verbs of this type:

No estoy seguro de que hagamos lo suficiente para proteger el medio ambiente. I’m not sure that we do enough to protect the environment. El presidente niega que el gobierno sea corrupto. The president denies that the government is corrupt.

The indicative is used in the subordinate clause when there is no doubt or uncertainty expressed in the main clause. Here is a list of some common verbs of this type:

No dudo que eres trabajadora. I don’t doubt that you’re hard-working. Estamos seguros de que el agua está limpia. We’re sure that the water is clean.

Quizás and tal vez are expressions that mean maybe, perhaps or possibly. They are usually followed by the subjunctive because they imply doubt or uncertainty. Quizás la tierra esté contaminada. Maybe the ground is polluted. Tal vez haga mal tiempo mañana. Perhaps the weather will be bad tomorrow.