Adult English-speaking American knows 42,000 words: study

Researchers developed a simple English test that was taken by almost one mn people

A native English-speaking American knows 42,000 dictionary words by the age of 20, a largest study of its kind has found.

Researchers led by Marc Brysbaert from Ghent University in Belgium developed a simple English test that has been taken by almost one million people.

It takes up to four minutes to complete and has been shared widely on Facebook and Twitter, giving researchers access to an unprecedented amount of data.

The test includes a list of 62,000 words that the research team compiled.

Participants were asked if the word on the screen is, or is not, an existing word in English. In each test, there are 70 words, and 30 letter sequences that look like words but are not actually existing words.

The test also asked for some personal information such as age, gender, education level and native language.

This enabled researchers to discover that the average 20-old native English-speaking American knows 42,000 dictionary words.

As we get older, we learn one new word every two days, which means that by the age of 60, we know an additional 6,000 words, researchers said.

The findings were published in the journal Frontiers in Psychology.