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“Lucy OS1 helped me discover I knew far more words than I thought”
Free Vocabulary Size Test
How many English words do you know? Answer 20 multiple-choice questions to find out your vocabulary size. No registration. Instant result with context on where you stand compared to native speakers and language learners.
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Your estimated vocabulary size
Lucy OS1 adapts its vocabulary to your word knowledge. Speak with Lucy OS1 to encounter new words naturally in context and expand your active vocabulary every day.
Research shows that understanding 95% of words in a text is the threshold for comfortable comprehension. For everyday English conversation, that requires roughly 3,000 to 5,000 word families. For reading newspapers fluently, you need around 8,000 to 10,000 words.
An average native English speaker knows between 20,000 and 35,000 words. University-educated adults often reach 40,000 or more. Lucy OS1 adapts to your current vocabulary size and introduces new words in context, which research consistently shows is the most effective way to expand vocabulary.
Common questions about vocabulary tests
The 20-question test uses words drawn from five frequency tiers, from the most common 1,000 English words to rare academic and literary vocabulary. It gives a statistically reasonable estimate of your total vocabulary size. For a more precise measurement, a dedicated study like the Vocabulary Levels Test uses 50 to 100 words, but our test gives a reliable ballpark in under 5 minutes.
Research published in linguistics journals estimates that native adult English speakers have a receptive vocabulary of 20,000 to 35,000 word families. University-educated speakers often score above 40,000. Non-native speakers at an advanced level typically know 10,000 to 20,000 word families, while intermediate learners know 3,000 to 7,000.
Encountering words in meaningful context is consistently the most effective method. Reading widely, watching native-level content, and having real conversations exposes you to new words alongside context clues that make them memorable. Lucy OS1 introduces vocabulary naturally in conversation, which means you learn words in context rather than from isolated lists.
This test measures receptive (passive) vocabulary, meaning words you can recognize and understand when you see or hear them. Most people's passive vocabulary is significantly larger than their active vocabulary, the words they use when speaking or writing. Your active vocabulary is typically 30 to 50 percent of your passive vocabulary.
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