Subjunctive in Noun Clauses 2 - Spanish Practice (Enrique ...
https://tildesites.bowdoin.edu/~eyepes/newgr/subj3.htm• DOUBT: When the main verb expresses doubt, disbelief or denial, the verb in the noun clause should be in the subjunctive: Dudo que vaya (I doubt that I'm going). In general, creer, no dudar, ser verdad , and other expressions of conviction imply certainty and therefore will not require a subjunctive in the clause that follows, while no creer, dudar, no ser cierto , etc., will: Creo que irás.