Language/Spanish/Grammar/Eso-Esto-Aquello

"Esta lección es para aquellas personas que tienen problemas con los pronombres demostrativos". 

¿Qué hay ahí? Estos pronombres son útiles cuando se refieren a un objeto o persona, y muestra la distancia entre, tu y el objeto. En el español es importante recordar cada cosa para tener una buena comunicación.

Esa / Ese / Eso.

This pronoun is used to referring to an object which is far.

"Esa/s" is for feminine objects or women. 
"Ese" is for masculine objects or a man.
"Eso" is for undefined objects or like plural of "ese" (Esos). 

"Esa casa es roja." (That house is red.)

"Ese hombre me ha golpeado." (That man has hit me.)

"Eso de allí es extraño" (That object from there is strange.)

Esta/ Este / Esto.

This pronoun is used to referring to an object which is near.

"Esta/s" is for feminine objects or women. 
"Este" is for masculine objects or a man.
"Esto" is for undefined objects or like plural of "este" (Estos). "

"Esta mujer a mi lado es mi esposa." (This woman by my side is my wife.)

"Este maletín contiene dinero." (This briefcase contains money.)

"Esto lo encontré en mi casa." (I found it in my house.)

Aquella / Aquel / Aquello.

It's the same as "Esa / Ese / Eso" but it's a little bit more formal or used in some countries in remplacement of "Esa / Ese / Eso ".

(Using a formal conjugation)

"Aquella señora es mi abuela." (That lady is my grandmother).

"Aquel es el edificio es el cuartel de policía." (That is the police department).

"¿Aquello es un avión?" (Is that a plane?).

Rules for his use

A basic rule to take in consideration, "Esa/Ese | Aquel/Aquella" is used forː

-An identified object, named in the sentence, distant.
-To point out an object. 

A basic rule to take in consideration, "Esta/Este" is used forː

-An identified object, named in the sentence, close.

A basic rule to take in consideration, "Esto" is used forː

-An object NOT identified, NOT named in sentence, nearby.

A basic rule to take in consideration, "Eso" is used forː

-An object NOT identified, NOT named in sentence, far.

A basic rule to take in consideration, "Aquello" is used forː

-An object NOT identified, NOT named in sentence, distant with formal use.