| It is certain | Es seguro |
| It is impossible | Es imposible |
| It is improbable | Es improbable |
| It is not possible | No es posible |
| It is not sure | No es seguro |
| It is not true | No es cierto/No es verdad |
| It is obvious | Es obvio |
| It is possible | Es posible |
| It is true | Es cierto/Es verdad |
| Not to be sure | No estar seguro |
| Not to believe | No creer |
| Not to deny | No negar |
| Not to doubt | No dudar |
| There is no doubt | No cabe duda de |
| There is no dought | No hay duda de |
| To be sure | Estar seguro |
| To deny | Negar |
| To doubt | Dudar |
| to believe | Creer |