The Em Dash—The Em Dash is the “giant hyphen” of the punctuation world. Many don’t realize that the hyphen is not the proper way to add commentary/editorial information into sentences. The example below shows the common mistake of using a hyphen rather than an Em Dash for this aside-type statement.
Ex. What is most important- especially for those not accustomed to certain exercise equipment -is that enthusiasm is not replaced with recklessness.
The sentence above is not incorrect in terms of syntax, semantics, or cohesion. The only thing that needs fixing are those pesky little hyphens. To create an Em Dash, type the first phrase and two hyphens. Leave no space between the words and the hyphens and no space between the two hyphens. Type the commentary phrase without adding a space after the hyphens. At the end of the commentary phrase, type two more hyphens with no spaces just like the first set. Most word processing programs will automatically turn your two hyphens into Em dashes. If it does not, you can select an Em Dash by going to the Insert tab of Microsoft Word, selecting Symbol, More Symbols, and then Special Characters. You can also use the shortcut key phrase Alt+Ctrl+Num or set your own shortcut key. The sentence in its corrected form is below:
Ex. What is most important—especially for those not accustomed to certain exercise equipment—is that enthusiasm is not replaced with recklessness.