How Many Words Does the Average Adult Know?
When you have very young children who are beginning to make sounds, doctors may ask you to count the number of words they know.
At first, it's easy. They can say "dog," "car" and "banana."
But then it may get difficult to count: you'll probably run out of fingers pretty fast.
So can you imagine counting the number of words that the average adult knows?
Experts have tried, but it's not easy. What kind of words do you count? How well should someone know a word?
The most recent major experiment was done by researchers from Ghent University in Belgium in 2016.
They made a list of 61,800 words, but this only included the basic form of each word. For example, they included "run" — but not "runs," "running" or "ran."
They didn't include proper nouns either, or multiword expressions like "peanut butter" or "bus stop."
More than 221,000 people took part in the experiment. They were given 100 words to look at. For each one, they had to say if they knew it.
They weren't asked to define the word, so it was enough for them to know that the word existed. However, in the list of 100, 30 words were not real.
When they looked at the results, the researchers said that the average 20-year-old native-speaking American knows 42,000 English words.
They said that on average, as people get older they learn one new word every two days, so by the age of 60 they know about an extra 6,000 words.
The research team said that it could be useful to compare their results with those of future experiments to see how English speakers' knowledge of words changes in time.
And similar experiments with non-native English speakers may show how well they know certain words — which could help English teachers.
