Let's dabble in punctuation for a while, OK?
Periods end declarative sentences and requests or mild commands.
Declarative: His name is Joshua.
Request or Mild Command: Please be sure to tell her I am coming.
If a sentence ends with an abbreviation, no additional period is needed. If the sentence requires a question mark or exclamation point, one may be added after the period.
Incorrect: Please make the check out to Roland N. Payne, D.D.S..
(Second period at end not needed)
Correct: Please make the check out to Roland N. Payne, D.D.S.
Correct: Do I make the check out to Roland N. Payne, D.D.S.?
A period is used after numbers and letters in outlines.
Outline:I. PunctuationA. Periods1. End sentences
A period always comes before a closing quotation mark.
Incorrect: George said, "I don't get it".
Correct: George said, "I don't get it."