Periods (also known as “full stops” or “full points”) are probably the most recognizable and widely used punctuation mark. Their primary and most common purpose is to end a sentence. But periods can (and should!) be used for a variety of other purposes as well, including creating acronyms and abbreviations.
Terms You Need to Know to Use Periods
STATEMENT/INDEPENDENT CLAUSE
An independent clause is a phrase including a subject and a verb that expresses a complete idea or thought. An independent clause is a complete sentence.
FRAGMENT
A fragment is a piece of a complete sentence. It is incomplete and should usually be avoided.
ABBREVIATION
An abbreviation is a shortened form of a word. It is generally used to represent the whole form when seen. Examples of abbreviations are the following: Dr., Mr., and Ave.
ACRONYM
Acronyms are abbreviations that typically use the first letter of a series of words to represent the whole thing. Examples of acronyms are the following: NASA, LOL, and NATO.
4 Ways to Use Periods
- Complete a Statement
- End a Fragment
- Create Abbreviations
- Identify Acronyms
1. Complete a Statement
DESCRIPTION
A period is used to complete a statement, which is a phrase that expresses a whole idea or thought.
APPLICATION
To use a period to complete a statement, simply put a period at the end of a statement that expresses an entire thought as the closing punctuation.
EXAMPLE
- Tommy’s favorite color is periwinkle.
- (This sentence expresses a whole thought, and so is a statement that can be completed with a period.)
2. End a Fragment
DESCRIPTION
A fragment is a piece of a complete sentence. It is incomplete and should usually be avoided. But in some cases, breaking the rules for emphasis can be acceptable if you do it knowingly and sparingly for rhetorical effect..
APPLICATION
To use a period to end a fragment, put a period after the end of the sentence fragment.
EXAMPLE
- Terry likes all kinds of ice cream toppings. Especially hot fudge.
- (The end of this example is the fragment. It is not a complete sentence, but it is treated like one with a capital letter at the beginning and a period at the end.)
- Note: there are other ways to punctuate this sentence that actually follow the rules—using an em dash between sentences would be mechanically correct. The period, however, provides a slightly different rhetorical effect.
3. Create Abbreviations
DESCRIPTION
Periods are often used in the process of shortening words to create abbreviations.
APPLICATION
To use a period to create an abbreviation, put a period after the last letter of the abbreviation.
EXAMPLES
- I’m off to Campbell St. to pick up my friend.
- (In this sentence, the abbreviation is the standard abbreviation for “street.”)
- Michael works as a volunteer with the fire dept.
- (In this sentence, the abbreviation is the standard abbreviation for department.. When the abbreviation is at the end of a statement there is no need to double up on periods.)
4. Identify Acronyms
DESCRIPTION
Acronyms are abbreviations that typically use the first letter of a series of words to represent the whole thing. Examples of acronyms are the following: NASA, LOL, and e.g. Some acronyms usually have periods, while others do not. It also comes down to the writing style guide that a company uses.
APPLICATION
To use a period to identify an acronym, place the period after each letter in the acronym.
EXAMPLE
- Wesley enjoys watching certain TV shows (i.e. dramas and comedies).
- (This sentence contains the acronym i.e., which is an acronym for the Latin phrase id est, meaning that is.)
NOTE: Not all acronyms require periods after each letter. Commonly recognized or widely used acronyms that your reader will immediately understand will not require periods between letters. For example, NASA, NATO, USA, FBI, TV, DVD, and many others do not typically include periods.