You know about 26,000 word families!

How accurate is this test?

This test was originally designed to test up to a maximum of 14,000 word families. Native English speakers and highly proficient non-native speakers of English, however, know far more word families than that. Therefore, the number of word families reported above is an estimate based on the performance of several hundred previous results. Your performance on this test ranks higher than 90% of all native English speakers who have taken this test without regard to age.

(according to vocabularysize.com - the distracting choices are intentionally quite attractive; you have to know the words well, and some of the items aren’t well designed - consider it noise; the result is still valid)