According to whom
Whose view is this?
Meaning
We can present an idea as someone's opinion or belief. This may be the speaker's view or someone else's, and naming it does not mean everyone agrees. Languages use words for thinking, viewpoint phrases, or special markers; some have no separate grammatical marker for this. Certainty shows how sure someone is, whereas this block shows whose view we are hearing.
How to spot it
Look for the person whose opinion, belief, or judgment is being presented, whether it is the speaker's or someone else's.
In your native language
English uses I think or I believe to present the speaker's view, and according to Nina to name another person's view or account. In my opinion and in my view clearly mark a personal judgment. A statement after think can begin with that, but that is often left out.
I think this chair is more comfortable.
I think marks this as the speaker's judgment.
In my opinion, we should start earlier.
According to Nina, this cafe has the best coffee.
The sentence presents Nina's view, not necessarily the speaker's.
In your learning language
Spanish introduces a viewpoint with según followed by a person, para mí, or en mi opinión. Creer que and pensar que report a belief, normally with the indicative, the forms used to state facts. After a negated belief such as no creo que, the following verb normally takes the subjunctive (subjuntivo), presenting the idea as not accepted rather than asserting it.
Según Diego, esta tienda cierra a las ocho.
According to Diego, this store closes at eight.
Según names the person whose information or view is being presented.
Creo que Elena tiene razón.
I think Elena is right.
The positive statement of belief normally takes the indicative tiene.
No creo que Elena tenga razón.
I don't think Elena is right.
The negated statement of belief normally takes the subjunctive tenga.
Learners whose language keeps the same verb form in positive and negative statements of belief may use *No creo que tiene razón. The usual form is No creo que tenga razón.