According to a recent study by Ghent University in Belgium, the average 20-year old American knows about 42,000 words. The article was published in Frontiers in Psychology, and findings were based on the result of a test that was distributed to a massive participant base of 1 million social media users on Facebook and Twitter.
The test asked participants to pick from a set of 100 random words – 70 were actual words, 30 were made-up ones. Users were asked to give their information (ie. age, gender, educational level, etc) so that researchers can collate the information.
If you’re curious as to your own grasp of the English vocabulary, you can take the test here. You’ll also be contributing to their research by doing so!