The punctuation of written texts, with which it is tried to reproduce the intonation of the oral language, constitutes an important chapter within the spelling of any language. It organizes the speech and its different elements and allows avoiding any text ambiguity that, without its use, could have different interpretations.
The following punctuation marks exist in Spanish:
Period/full stop .
Suspension points …
Question Marks ¿?
Exclamation points ¡!
Parenthesis ( )
Square bracket 
Quotation Marks " ", ´ `, « »
Let me start by pointing out some of the uses of the Period/full stop (.)
The PERIOD (.) indicates the pause that occurs at the end of a statement. After the PERIOD or full stop – with the exception of the one used in abbreviations – a capital letter MUST be written. There are three ways to use the PERIOD in Spanish:
a) To separate statements that form a paragraph. After this PERIOD another sentence is written on the same line. If the PERIOD is at the end of the line, the next line begins on the following one without leaving any margin.
For example: Salieron a dar un breve paseo. La mañana era espléndida. (They went for a short walk. The morning was splendid.)
b) To separate two different paragraphs, which usually develop different contents, within the text unit. After this PERIOD, the new paragraph is written on a different line. The first line of the new paragraph MUST have a margin greater than the rest of the lines that compose it, i.e., it needs to be indented.
For example: El mar estaba embravecido aquel día. Los barcos bailaban sobre el agua sorteando las olas con dificultad.
Miguel, sentado en el muelle, esperaba el regreso de su padre. Atisbaba el horizonte buscando ansioso su barco con la mirada.
(The sea was enraged that day. The boats danced on the water going around the waves with difficulty.
Miguel, seating at the dock, waited for his father’s return. He was watching the horizon looking anxiously for his boat.)
c) The FULL STOP is the one that closes a text.
Another use of the period:
The period is also used after abbreviations. Examples: Sra., Excmo., Cf.
Combination of the period with other signs
It is often necessary to combine the period with other signs that also close periods, as the parentheses or the quotation marks. In these cases, the period is always placed behind the closing quotation marks, square brackets or parenthesis.
For example: Sus palabras fueron estas: «No quiero volver a verte». Después cerró de golpe la puerta de su casa. (Creo que estaba muy enojada). (Her words were these: "I do not want to see you again". Then she slammed the door of her house. (I think she was very angry).
Incorrect use of the period
The full stop is not used after titles and subtitles of books, articles, chapters, works of art, etc., when they appear alone.
Examples: El llano en llamas
La Venus del espejo
***** More to come on the other punctuation signs used in Spanish *****