And Another Thing
If "such as" introduces a nonessential clause (Some drivers, such as teenagers, get in more accidents than others), you put a comma before it. If it introduces an essential clause (Drivers such as teenagers get in more accidents than others), there is no comma before or after it.
Wrong: Some alcoholic beverages, such as, margaritas and daiquiris, can have as many calories as a burger.
Why: There's a comma after "such as."
Right: Some alcohol beverages, such as margaritas and daiquiris, can have as many calories as a burger.
Why: This one's plain and simple: It's never appropriate to put a comma after the transitional phrase "such as" (same with "including"). Other methods of introducing examples, however, such as "for example," "namely" and "for instance," are always followed by commas.
Next, when verbs come in pairs …