grammar.subjunctive.doubt-denial
Doubt and denial: no creo que, dudo que
Negated belief and doubt flip to the subjunctive: creo que viene (indicative) vs no creo que venga. Dudar que, negar que, no es cierto que.
⚠ Stub: AI-drafted outline, not yet reviewed. The structure is permanent; the content will be expanded.
grammarB1, B2stubdraftv0.1.0
Explanation
The polarity switch is the heart: creo que / pienso que / es verdad que + indicative; their negations + subjunctive: no pienso que sea buena idea, no es verdad que cueste tanto.
Dudo que and niego que are subjunctive even unnegated; no dudo que (certainty restored) goes back to the indicative. Questions with creer allow either, signaling the asker's stance.
Examples
No creo que llegue a tiempo.
I don't think he'll arrive on time.
I don't think he'll arrive on time.
Region: global
No dudo que es buen profesional.
I don't doubt he's a good professional.
I don't doubt he's a good professional.
Region: global