Bruuh, fleek, tfw, famo — while it’s possible that you’ve seen or heard at least one of these words before, you almost definitely didn’t encounter any of them more than two years ago. That’s because they’re all new words that emerged in the US over the course of 2014. A forensic linguist has been using Twitter to analyze the new American vocabulary; his research uses the geotagging data in tweets to track the emergence of words that became common during 2014. This video takes a look at a few of those words, where they came from, and the broad categories they tend to fall into. For a more detailed look at the study, check out Quartz’s interactive feature.