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    Answer a few questions

    We've created more than 120,000 questions designed to help you learn words.

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    We build a model of your knowledge

    Our magical technology models your brain. The more you play, the more we know about your vocabulary knowledge.

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    We predict which vocabulary words you don’t know and teach them to you

    Get a question wrong? We’ll schedule Review and Progress questions so that you’ll learn the word, and won’t forget it in the future.

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    You learn useful words and improve your vocabulary

    Track your progress as you quickly master the words that are essential to success in an academic or business environment.

What is is the easiest, most intelligent way to improve your vocabulary. It combines an adaptive learning system (The Challenge) with the world’s fastest dictionary (The Dictionary) so that you can more quickly and more efficiently learn words.


We teach you useful words.

We don’t waste your time. We start by looking at books, periodicals, and other material that cumulatively contain over 1.6 billion words. From this corpus, we pull out the most essential English vocabulary words, the words that you need to succeed in an academic or business environment. This list serves as the basis for our learning platform.

We teach you only the words that you have trouble with. uses a proprietary technology that we call Adaptive Vocabulary Instruction or AVI. Unlike traditional learning systems, we don’t rely on a series of time-consuming and boring assessments. Instead, everything you do on the site adds to our AVI model. It’s like you have a personal trainer in the room, monitoring your work and suggesting new words and exercises to challenge you on your level. Because of this, you don’t waste your time learning words that are too easy or too hard.

We don’t let you forget.

Finally, we analyze your achievements, and reinforce your skills by reintroducing words at various times to make sure that you are retaining the words you originally learned

The Challenge

Challenge Question

A Whole Lot of Questions, a Whole Lot of Learning

The heart of The Challenge is more than 100,000 vocabulary questions that are designed to evaluate and teach vocabulary words. Each question tests a particular meaning of a word, provides helpful hints, and is followed by an explanation of the correct answer. Many studies have shown that the best way to learn is through multiple exposures to a word, with challenging questions that make you think. That’s what we provide.

Question Graph

It's Like a Personal Trainer for Your Brain

We use our own adaptive learning system to ensure that you get the right question at the right time. We build a model of your vocabulary and abilities as you answer each question, and then serve you up with questions that are not too hard and not too easy. From the results of these questions, we determine what words to focus on in your personalized learning program.

Vocabulary List

A Personalized List of Words Just for You

As you answer questions, we begin to compile a list of words to learn. If you get a question wrong or choose to use a hint, the word is added to the list. Once we add a word to this list, we keep working with you until you’ve mastered that word. You can see your list by clicking on the My Progress tab on the top of the screen.


Hints and Explanations Help You Learn

If you’re having trouble with a question, we will sometimes provide a hint to help you along. Depending on the word, you can use your hint to eliminate a choice, to see sentence examples, or to see definitions of the word. If you get a question wrong, we provide you with a friendly description of the word. Read it! It’s designed to help you remember the word.

Path to Mastery

A Path to Mastery

If you answer enough questions correctly on a word that you’re learning, you’ve mastered it. You can see the progress on one of the words you’re learning in the small bar graph next to the word. Once you’ve mastered a word, the bar turns gold.

Four Question Categories

On the upper right hand corner of each question is a question category and a point value. There are four question categories:

  • Assessment - These questions can be about any word and are chosen based on how you’ve done on all previous questions. (100 points without a hint, 50 points with a hint)
  • Review - If you get a question wrong or ask for a hint, we’ll give it to you again as a review question. (75 points)
  • Progress - Once a word has been added to the list of words you’re learning, we’ll continue to ask you new Progress questions about it until you’ve mastered the word. (100 points)
  • Mastery Review - Even after you’ve mastered a word, we still check up on you every once in a while with a Mastery Review question. (100 points)

Earn Points and Achievements

Earn Points and Achievements

As you answer questions correctly and learn words, you earn points. And as you earn more points, you are assigned a badge that represents your level. You start as a “novice,” and then as you hit different point goals, you’ll earn new badges.

You can also earn extra badges based on various achievements, such as answering 5 questions correctly in a row, or acing a round. Click on My Profile to see a list of available achievements and levels.

Chart Your Progress

Chart Your Progress

You can find out more about how you’re doing by clicking on the My Progress tab. From there you’ll see charts on overall progress, as well as progress on any individual word.

The Dictionary

The World’s Fastest Dictionary

The dictionary is designed to be the fastest, most useful English dictionary in the world. Unlike most online dictionaries, we want you to find your word’s meaning fast and then get on to better things. We don’t care how many ads you see or how many pages you view. In fact, most of the time you’ll find the word you need after typing only one or two letters.

Predictive Magic

Predictive Magic

Our search box is smart. So smart that it predicts what you’re looking up as you type. Try it. You’ll see that as you type, we’re making our best guess as to what word you’re looking for. If you see your word in one of the first five choices, you can click on it to see the word page, or if your word is number one, we’ll choose it for you.

Easy-to-Read Definitions with a Little Bit of Attitude

Easy-to-Read Definitions with a Little Bit of Attitude

We made an exhaustive review of the dictionaries out there, and we came to a not-so-startling conclusion. Current dictionary definitions can be difficult to understand and not much fun to read. This is OK if you’re looking up a word for reference, but if you’re actually trying to learn how a word is used in the real world and to make it part of your vocabulary, the typical dictionary definition is not going to do it.

Our dictionary is different. Most vocabulary words include a short blurb that describes what the word means and how the word is used. These blurbs are easy to understand and fun to read. If there’s an entertaining story about the word, we include it. If the word can be confused with another, we include that information as well. The point is to help you learn and remember the words you look up without having to look it up a hundred times.

Ever confuse affect and effect?

Ever confuse affect and effect? flair and flare?

We’ll help you out. For all the most confusing English words, we’ve provided articles that describe the difference. So if you look up affect, you’ll see both a short blurb describing the word as well as a longer discussion of how it differs from effect.

Over 100 Million Sentence Examples

Over 100 Million Sentence Examples

Each word has usage examples from our corpus of over 100 million sentences. You’ll see how words are used in edited language by some of the best writers in the world, from periodicals such as The New York Times, Scientific American, and from great works of fiction by writers as diverse as T. S. Elliot and Upton Sinclair. Seeing a word in context is a great way to understand how it’s used in the wild.

Keep Track of Your Favorite Words with Vocabulary Lists

Keep Track of Your Favorite Words with Vocabulary Lists

One of the best features of is that you can easily make and share Vocabulary lists. Create a Vocabulary List quickly from assigned words, grab words from any text, or generate a list from the Advanced Search. Then, you can add descriptions to words, name your list, make your list public, and share it with your friends.

Share the Wealth, Share your Words

Share the Wealth, Share your Words

By making your vocabulary lists public, you can share them with your friends and colleagues. People can comment on the lists, favorite them, and even use them as the basis for a new list.

How the Blog Works

Check Out Our Blog

If You Really Love Words, Check Out Our Blog.

The Blog features articles about language and the creative process written by a super talented group of writers, linguists, and other word mavens. You’ll find articles about new words being used in the news, discussions about grammar, and research into how dictionaries are put together.

It’s More than a Blog; It’s a Community

The people who read our blog participate through comments and article suggestions. By reading, you are joining a community passionate about words, language and creativity.