This may or may not turn into a series of short posts on my experience of trying to use the COCA corpus in class. Inspired by the comments to this post by Kevin Stein/@kevchanwow.
A student in my TOEIC class, when we were looking at adjective endings -ED and -ING, asked what was the difference between “unmotivated” and “demotivated”. I replied that demotivated describes someone after some experience whereas unmotivated is a general state of being. I wasn’t too sure if that was sufficient so whilst the class was engaged in the following part of the lesson I used the wildcard asterisk, see image above.
And found out that the instances of “demotivated” were pretty low compared to “unmotivated”. I only transmitted the frequency information to the said student. If I had more time and a projector hooked up to the computer I would have looked at the example sentences in each case.
Do let me know of any searches you have done in class.