Use an italic word to accentuate titles that can stand alone in a sentence, according to the Capital Community College Guide to Grammar and Writing. (Reference 1). For example, only the title of the play Wicked is in italics in this sentence, "Mary saw the Broadway play Wicked, three times."
Use italics to imply emphasis to a word to reach the desired effect. In this sentence the emphasis is on what not to do, "I told you never to cross that busy street, Danny." The word never is italicized.
Accentuate a sound when you use an italic word in a sentence. Rather than simply saying what something does, show it with italics. An example you can almost hear the water rushing when you read the first word, "Whoosh, the freezing water rushed past her."
Draw attention to specific words in a sentence with italics. An example of this would be to type, "There are too many ifs and ands in the paragraph." The words -- ifs, ands -- are italicized in the sentence.
Use normal font when you use an apostrophe-s to form a possessive word, such as, "Have you read the Tribune's piece on web content writing?" Tribune is italicized but the apostrophe and s are not.
Apply a normal font for punctuation. This includes periods, commas, question marks and parenthesis. Italicize punctuation in a title when the punctuation is part of the title, such as, "Have you read Bill Martin Jr.'s, Brown Bear, Brown Bear, What Do You See?" Brown Bear, Brown Bear, What Do You See? is italicized.