During the past several years I have noticed that the word during has joined my list of disappearing words. The phrase over the course of has replaced it. My dictionary defines during as “throughout the entire time of,” “at some point in the entire time of,” and, oddly enough, “in the course of.”
As in most of the other examples on which I have posted, “over the course of” is not wrong or should never be used. I just notice that speakers use it almost exclusively instead of using “during.” Once a polysyllabic word or phrase like this catches on, the shorter, more concise word seems banished from the language.
Using “over the course of” seems appropriate when describing something that occurred consistently or repeatedly throughout a span of time. “Gas prices usually rise over the course of the summer,” seems correct. You could also say, however, “Gas prices usually rise throughout the summer,” or ” … during the summer.”