You’ve probably heard of freerice.com. It gained popularity a few years ago, and while it’s no longer the crazy fad it was, it’s not any less useful for vocabulary building. Here’s how it works: you answer a multiple-choice vocabulary question, and for each correct answer, ten grains of rice are donated to the World Food Programme, an initiative of the United Nations. My favorite thing about Free Rice is that it’s adaptive—that is, every question that you get right increases the level of difficulty of subsequent questions. And unlike many free online vocabulary activities, there’s plenty of room to grow on Free Rice. The English vocabulary section (yes, there are lots of subjects you can be quizzed on) has sixty levels, ranging from elementary-school level to words many native speakers have never even heard, let alone understand. I found the teens (about levels 10-16, to be exact) to contain the most TOEFL-appropriate vocabulary. Be forewarned, though, that because the program uses synonyms rather than definitions, you won’t get a full understanding of new vocabulary from this site alone. So while you can use Free Rice to quiz yourself and find new vocabulary to learn, be sure to look up any new words in a dictionary and find example sentences elsewhere.
It may not be the most innovative name in the industry, but don’t let that lower your expectations. Like Free Rice, Vocabulary.com uses an adaptive system to choose words that fit your level. If you create an account, your information will be saved so you can continue to review words that you miss in later sessions. Once you correct an incorrect answer, you can view an explanation. My only complaint so far with this website is that the explanations and example sentences can be overly complex.
If you know Sporcle, you may be surprised to see that you can use it for studying. Sporcle is a quiz website that caters to lovers of film, literature, music, and randomness. If you can get past all of the irrelevant (but entertaining) matching and fill-in-the-blank games, you will find the “Language Quizzes” section. Subsections include “Vocabulary”, “Begins and Ends” (where you play with letters by adding or removing letters from the beginning or end), and “Definition.” At the end of the quiz, a quick look at your statistics will show you how your results compared to those of other test-takers.