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dudar
to doubt (subjunctive)
negar (e:ie)
to deny (subjunctive)
no creer
to not believe (subjunctive)
no estar seguro/a (de)
to not be sure (subjunctive)
no es cierto
it's not true; it's not certain (subjunctive)
no es seguro
it's not certain (subjunctive)
no es verdad
it's not true (subjunctive)
es imposible
it's impossible (subjunctive)
es improbable
it's improbable/unlikely (subjunctive)
(no) es posible
it's (not) possible (subjunctive)
(no) es probable
it's (not) probable (subjunctive)
no dudar
not to doubt (indicative)
no cabe duda de
there is no doubt (indicative)
no negar (e:ie)
not to deny (indicative)
creer
to believe (indicative)
estar seguro/a de
to be sure (indicative)
es cierto
it's certain (indicative)
es seguro
it's sure/certain (indicative)
es verdad
it's true (indicative)
es obvio
it's obvious (indicative)
quizás, quizá, tal vez, acaso
Maybe (subjunctive)
es evidente
it's evident (indicative)