Quotation Marks

Always place commas and periods within close quotation marks. In England, the custom is to write She said he was "intelligent". But in the United States, the convention is to write She said he was "intelligent."

You might notice that placing quotation marks around the word intelligent casts doubt on the man's IQ. Maybe he is not intelligent, the quotation marks imply. This use of quotation marks is but one of many ways punctuation can be used to convey important meanings, but writers who do not know the conventions of punctuation will not be able to make use of these important writing tools nor will they truly understand the writings of other people who do know the conventions.