When looking at a list, the words with a green check are what we call “learnable.” For these words, we have written a descriptive definition and have prepared sufficient questions to thoroughly test knowledge of the word in multiple senses.
If your list does not contain at least 10 learnable words, you will see "filler" questions when practicing the list. Filler questions may be on words from your other lists, or other words that are in your learning program.
We currently have over 15,000 learnable words and continue to add more daily.