Vocabulary test: how many of these words do you know?

How the vocabulary test works

Each screen shows a single word and two buttons, Yes and No. Press Yes if you know the word well enough to explain it to someone else, and No if you don't, or if you only have a vague feeling you have seen it somewhere. There is no clock, and the whole test takes about two minutes.

The 30 real words run from ones you meet every day, such as garden and window, to words that turn up only a few times in a lifetime of reading. The order is shuffled for every round, so there is no fixed spot where the made-up words sit. The shuffle comes from a random number stored with your round, which means any round can be replayed in the same order if something looks wrong.

How the score is calculated

We take two numbers. The first is the share of the 30 real words you said yes to. The second is the share of the 10 made-up words you said yes to. Your score is the first minus the second, shown as a number from 0 to 100 and rounded. It never goes below zero.

An example: you say yes to 24 of the real words and to 1 made-up word. That is 80 percent minus 10 percent, so your score is 70. If you had said yes to 27 real words and 4 made-up ones, you would have recognized more real words and still ended up lower, at 50.

Your result shows the score, the band it falls in on this test (0 to 19, 20 to 39, and so on up to 80 to 100) and how many words of each kind you said yes to. We show typical scores once enough people have played. Until 50 people have finished the test, your result says you are one of the first players; after that it shows what percentage of all players you scored higher than.

Why a yes on a made-up word costs points

A test that only asks "do you know this word?" rewards confidence. Two people who know exactly the same words can end up far apart if one of them says yes whenever a word feels familiar. The made-up words are there to catch that. They follow English spelling patterns, and a few have endings that look like rare Latin-based words, so they don't stand out. We checked every one of them against two English word lists with more than 270,000 entries each, and none of them appears in either.

If you said yes to two or more made-up words, your result says so in plain terms. That usually means some of your yes answers on real words were guesses as well, and those guesses are what the deduction takes back out.

What the score does not say

This is a short test with one kind of question. It says how you did on these 40 words today, compared with other people who took the same test. It does not estimate how many words you know in total, and it says nothing about reading, writing or how well you use the words you know. A native speaker and a fluent learner can reach the same score for very different reasons.

From one test to the full Brain Check

The vocabulary test is separate from the Brain Check, which has five games of 45 seconds each: remembering squares on a grid, reacting to dots, spotting patterns, finding differences between two pictures and doing quick sums. It takes about five minutes and ends with a score from 0 to 100.