There's a website called manilex.com, M-A-N-Y-L-E-X. You go on the website, and it does a little vocab test for you. And then from that sample, they do a projection for how many words you probably know. So based on a little sample, they project that out to get an estimation of your vocabulary size. Generally speaking, native speakers know between 20,000 and 30,000 words somewhere in that region for most native speakers. I got about 25,000 words in the test. So that puts me slap bang right in the middle of that range.