English-Corpora.org is a great resource for teaching language, variation and change in action. This page offers some suggestions about how you might use it in a pedagogical setting. Contact Heather Froehlich (hgf5@psu.edu) if you want help implementing these strategies in your classroom.
What can we learn from news discourse?
Choose a major topic or issue that was popular in the past five years and develop some search terms - such as questions of climate change or migration - and observe how these topics are discussed in very close detail using one aggregated search of many of different news sources. What rhetorical strategies do different sources employ? What does that look like? How do different countries report on the same issue?
How do we use words and do they change their usage or meaning over time?
Using the Corpus of Historical American English or the Corpus of Contemporary American English, choose some keywords to start with that are interesting to you. Do they rise and fall over time, or do they stay pretty consistent? The Corpus of Contemporary American English is especially fun for tracking slang usage since 1990. Watch the rise and fall of "on fleek" or "woke". The Corpus of Historical American English is especially useful for thinking about how a particular word has been used over the past century. And, you can always check to see if something has entered the cultural zeitgeist enough to make it to TV or movie scripts (or soap operas).
I want to check something weird I saw somewhere online. I think it's wrong!
Resources like the Global Web-Based English corpus are really helpful for observing newer forms of words you haven't seen before -- where else is this construction used? Or is this really just a one-off weird thing? (hint: it's probably not.)