Why is " to think" or "To believe" indicative?

Question

If indicative has to be factual, truthful, or a "certainty" how can to think or to believe be indicative?

to think something does not make it factual or certain same goes for believing something. someone please explain how these words trigger the indicative?

Answer 1

Certainty is not the criteria. It is probability.

Though, phrases like es cierto que o es verdad que take the indicative so does creer if you are stating something that is likely to happen or to exist.

To trigger the subjunctive it has to be contrary-to-fact, or highly improbable. This is often confused with expressions of doubt which tends to make one think that anything that is not certain then is doubtful, therefore, improbable. Not so. Expressions of doubt employ "special verbs" to show doubt such as dudar, no creer que, negar, no estar seguro de, no pensar, etc.

No dudo, no pienso, no creo que are stating that it is unlikely or improbable. Not that it is not a certainty. It is not probable.

Therefore, I can say creo que to mean it is probable (in the future)(though not a certainty) and use the indicative. You don't have to be 100% certain of something to use the indicative mood, just be stating that in the future it will probably happen or exist. (similar to the future tense used for conjecture)

See the slideshow on subjunctive use below:

Subjunctive mood

Answer 2

In Spanish Yo creo and Yo pienso denote certainty, even if they do not in English. It's just one of those things you have to accept! However No creo and No pienso do require the subjunctive. Also remember ¿Crees que sea difícil la tarea? Do you think the homework is/will be hard? You do need the subjunctive when creer is in a question.

Answer 3

Like Dandi has said, statements like "I believe/I think" denote certainty. As a result, the clauses that follow these statements are statements of fact or declarations of what the speaker considers to be true. If you were to take the negative of these sentences "No creo que/no pienso que" then you introduce doubt or uncertainty, so the clauses that follow these statements become non-declarative because they describe contrary-to-fact/hypothetical conditions or conditions that you are uncertain of.