Punctuation is a tool for shaping sentences and creating word flow. It also directs writing and creates easier sentence comprehension. Unfortunately, I catch myself misusing punctuation frequently. At times, I have difficulty following the guidelines for using an apostrophe.

The apostrophe indicates the possessive case of nouns and pronouns and creates a contraction of several words. Below is a sentence where I mistakenly used an apostrophe.

Her husband, Tim, was in his 50's, but he looked like a 30-year-old.   

Her husband, Tim, was in his 50s, but he looked like a 30-year-old. 
          *correct use

We use apostrophes to indicate that something has been omitted from a word or a number. Don’t use an apostrophe for plurals of numerals or multiple-letter combinations.

I’ll also study the punctuation rule of commas. A comma creates a short pause within a sentence. If a comma doesn’t help make the sentence clear, it should not be there. If removing a comma creates misinterpretation, then use the comma. Below is a sentence where I mistakenly used a comma

The girl, who is standing on the corner, is my sister.

The girl who is standing on the corner is my sister.         *correct use

An essential clause or an essential phrase must not be set off from the rest of a sentence by commas. The phrase further defines the word “girl” and is restrictive. Another mistake can be found in the next sentence.

          Sam reportedly told the press about his, "secret life in the CIA."

          Sam reportedly told the press about his "secret life in the CIA."       
          *correct use

The comma before the quotation is not necessary because the quoted material depends on the rest of the sentence for its context. There are many other rules I need to work on, but I still have an entire semester ahead of me for reviewing!