Frases de duda y certeza

dudar que

dudar que

to doubt that

es dudoso que

it's doubtful that

es improbable que

it's unlikely that

es posible que

it's possible that

no creer que

to not believe that

no es cierto que

it's not true(certain) that

no estar seguro

to not be sure that

no parecer que

to not appear that

no pensar que

to not think that

negar que

to deny that

no es verdad que

it's not true that

no dudo que

to not doubt that

estar seguro de que

to be sure that

creer que

to believe that

no negar que

to not deny that

es verdad que

it's true that

es cierto que

it's true(certain) that

saber que

to know that

no estar seguro de que

to not be sure that

es probable que

it's probable that

es imposible que

it's impossible that

es evidente que

It's evident that...