that
In Spanish, 'eso' is used to represent something that is not near the speaker but not as removed as something that might be referenced using 'aquellos' or 'aquellas'. It is a demonstrative pronoun, acting not only as a pointer but as a noun replacement to avoid redundancy or over-specification. However, 'eso' is also used in an idiomatic or abstract sense to mean 'the thing is,' or 'that's the problem,' amongst other things.
That was yesterday.
This phrase is used to refer to past events.
That is a book.
The phrase is a basic statement pointing out an object and identifying it.
That is not true.
This phrase is often used when disagreeing with someone or referring to an incorrect fact.
This phrase is used when expressing confusion or lack of understanding about something.
None
Is that yours?
It is a question asking about ownership of an object.
I am sick of that.
This phrase is used to convey strong dissatisfaction or frustration with a situation.
I believe in that.
It is a statement of affirmation or belief.
That is far.
This sentence is used to indicate distance.
That is strange.
It is a sentence used when something does not fit the normal or expected pattern.