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Let’s talk about that punctuation mark, the period. The simple one at the end of your phrases. One who allow you to absorb the idea that you have read and catch your breath. This punctuation mark does have some basics rules. First and simplest one, just to put one at the end of your sentences. However, from time to time, you may have some problems to know where to put it. That is when other punctuations marks get in the way. If you can speak French, you would have an advantage on these; «?» and «!» —  Here’s why, they are call “question period” and “exclamation period”, you would know that you don’t have to put a period after that period. Hereby, you should never finish your sentence like theses:

— Do you like chocolate?.
— Yes, I love to get some!.

punctuation

In the same vein, you do not put two consecutive periods at the end of the sentence. It is the same with sentences that end with an abbreviation. – To make thinks more difficult, even if the period of that abbreviation is inside quote marksYou should not put a second period after a sentence if it is a complete phrase. “I tell you to do it just like that.” But, if it is not a complete one, it“should be outside”.
For parentheses, you should do the same as for the quote marks.
Some say that an old habit has been transfer from typing with a typewriter to computer, the two spaces after the period. That is really not necessary anymore, except if you use a font that feel like a typewriter and want it to look like an old typesetting made on that kind of machine. Today’s typographers remove them for a better flow in the paragraph.
Last and not least, other uses of the period are in lowercase abbreviations and sometimes also in uppercase for academic degrees. Here’s a link to the “Canadians Who’s Who” website that has a nice list of abbreviations .