Punctuation is the standard grammatical markings within sentences. The various types of punctuation consist of the period, the comma, the semicolon, the colon, the dash and the apostrophe. The punctuation helps to form complete sentences, to separate ideas, and to convey an idea more clearly. You need to check for punctuation when proofreading a paper, because as you are writing, you may not realize that you made a punctuation error. Understand the different types of punctuation, read each paragraph aloud, and then have someone else read over your paper.
Compare your writing with sample sentences in a grammar book. Grammar books often have practice exercises with sentences that relate to the topic being discussed. For example, if you want to check the use of a comma, then look at the exercise that corresponds to the section on commas. Grammar books can be found in the bookstore, online and at the library.
Distinguish between a sentence and a fragment. A sentence is a complete thought with a subject and a predicate. It begins with a capital letter and ends with a period. A fragment is a group of words that does not contain a subject and predicate. An example of a sentence is "I liked the book." An example of a fragment is "The way in which." Read the paragraph aloud, and make sure that your sentences have the correct structure. If you find any fragments, revise them.
Understand the use of the apostrophe. An apostrophe is used to show possession, or to form a contraction. For example, if the book belongs to Amy, then you would write "Bonnie read Amy's book." If the subject is plural, then the apostrophe comes after the word; for example, "Amy read the students' essays." A contraction is a shortened form of a word, such as "don't" for "do not." As you read the paragraph aloud, fix any errors that correspond to the use of apostrophes.
Make sure that you put commas in the proper places. Check that your commas are in the correct place within a sentence. Commas are used for creating a list; for example, "Amy has tissues, napkins and paper towels." Use a comma to join sentences with a conjunction, such as, "Carly has a new idea, but Amy does not." Commas are also used to provide information that does not affect the meaning of the sentence if removed. An example of this is "Carly's dress, which was once Amy's, is black." The sentence still makes sense if you write it as "Carly's dress is black." When you read your paragraph, examine the position of the commas and fix any errors.
Put the semicolons in the proper location. A semicolon is used to connect two complete sentences. For example, "Amy has a pleasant disposition; she will always persevere." Each of these independent clauses can stand alone. Often, people make the mistake of using a comma in place of a semicolon. Be sure to fix such an error if you made this mistake.
Recognize when to use a colon. You use a colon in order to introduce a concept or idea. For example, "There is one thing that Carly does not want: confrontation." By reading your paragraph aloud, and paying attention to the emphasis of the ideas you present, you can determine whether you need to add a colon.
Comprehend the use of parentheses and the dash. Parentheses are placed around a word or idea for emphasis, such as "Carly (not Amy) writes rapidly." The dash is used to emphasize a particular part of the sentence. It is stronger than the comma and parentheses. It is not used frequently within formal writing. For example, "Chris said that following directions -- the most important thing in this world -- is crucial to success." While reading your paragraph, determine if any of your ideas require such emphasis.
Analyze the placement of periods, commas, colons and semicolons when using quotation marks. Periods and commas are placed inside quotation marks, and colons and semicolons are placed outside quotation marks.
Have your friend read your paper after you have proofread. Have your friend read it out loud. Another person may find mistakes that you did not notice.