The best way to know when NOT to use a period is to understand when to use it. This is an important punctuation mark indicating the end of an entire thought or sentence. You wouldn’t use it to indicate a question, break up a sentence or make a list. These require other punctuation marks.
Defining a Full Stop/Period
A full stop period (.) is a punctuation mark that shows the reader the end of a complete thought. Sometimes this can be phrases, but it’s mostly for whole sentences. They are also appropriate for abbreviations and initials.
Samples of Incorrect Use of a Period
The following samples will show the correct and incorrect ways to use a period. It’s pretty straightforward, as you will soon see. But if you can remember these little rules, it will be much easier as you go along.
Never use a period to ask a question or make an inquiry:
Correct: Did you see that cat?
Incorrect: Did you see that cat.
Breaking Up Sentences
There’s a difference between ending a phrase and then breaking up a sentence with a period.
Correct: Understanding and kindness.
Incorrect: The world needs. Understanding and kindness.
To make the incorrect sentence better:
Understanding and kindness are what the world needs. (no punctuation)
Here’s what the world needs: understanding and kindness. (colon)
In regards to the world, it needs understanding and kindness. (comma)
Understanding and kindness; such things are what the world needs. (semicolon)
When listing items use a colon (:) or Em-space (–).
Here’s the shopping list: eggs, bananas, bread, milk and flour.
Here’s the shopping list – eggs, bananas, bread, milk and flour.
However, you can make it vertical too. But, only use a period after each list item when they create a full sentence.
Get grandma at 9 A.M.
Go to the grocery store.
Call Mr. Smith.
Salon appointment at 3 P.M.
Note the last example of the to-do list. There are two periods in the abbreviations for morning (A.M.) or evening (P.M.) However, periods also abbreviate things like titles, prefixes, initials and others.
Using a period is simple and basic. You use it to indicate a full sentence, an idea, or as an indicator for abbreviation. All other ways will likely be wrong.