When it comes to word learning, a lot of people will ask, "How many words should you learn in a day?" Setting a daily goal makes any long-term learning or self improvement project less overwhelming. You don't need to confront the enormity of the goal, just the day-by-day experience.

The only problem with this one-day-at-a-time approach when it comes to learning words? The number of words you can learn in a single day is zero.

"What?!" you may be wondering. How is it possible you can climb a mountain, fly halfway around the world, even just clean your room in less time than it takes you to master an arcane vocabulary specimen such as noetic or absquatulate or chthonic

The answer is that your brain doesn't retain anything you learn in a day...long-term. Think about it: Your brain is a busy organ. It has to regulate all the systems that keep you alive, not to mention figuring out where you put your cell phone and how much tip to leave on a $12.85 lunch tab. A word you learned last Tuesday but haven't called to mind since can hardly compete. Your brain probably decided the word's something you won't ever need again and jettisoned it within 24 hours of your first committing it to memory.

Which is why, if you genuinely want to learn a word, you have to show your brain that it's important to you. How? Learn it on Tuesday, then look at it again on Wednesday. Take a peek on Thursday. And again Friday. Enjoy a weekend off and then after a quick review on Monday, your brain will probably remember the word for a full week without seeing it again, then a month after that. Maybe, with enough reminders, spread further and further apart, you'll be able to get your brain to remember...well, not forever — brains don't work that way — but for a very, very long time. 

Check out the way blog writer Language Surfer, a.k.a. Ron Gullekson, describes his process of introducing new words into his working vocabulary:

One of the most important things to keep in mind is that you rarely learn a vocabulary word the first time you see it, or even the first day you see it. You have to review a word again, and again, and again. I’ve seen estimates that say it takes seven meaningful exposures to really learn a word, but I wouldn’t be surprised if it’s closer to 20 or 30 exposures.

And these exposures can’t all come in the same day. A word is really “acquired” when you’ve seen it again and again over a period of time–weeks and months.

What Gullekson calls acquire we at Vocabulary.com call master. Mastering a word in our game means you haven't just got a few questions right on that word. It means you have seen questions on it over and over again, throughout the course of actual time. No one, no matter how many hours they play, will be able to master a word in a single day. Your progress bar does not change from green to gold so easily, which is one of the reasons it feels so good when it does. 

Want to learn more about the science behind Vocabulary.com? Read an excerpt from New York Times Magazine science reporter Benedict Carey's analysis of new studies of our question-based approach or our own white paper on gamified word learning.