Developing solid TOEFL vocabulary skills can be one of the most challenging parts of studying for the exam, but it’s also one of the most important. Many TOEFL questions either ask you the definition of a word outright or require you to have knowledge of certain words in order to answer a question correctly. With so many words in the English language, which are the ones you need to know? We’ve done the hard work for you and determined the 400 most have for TOEFL words to know. They’re all listed in this application, along with a definition and sample sentence for each as well as audio for both words and sentence examples. We also end with tips on how to use this list most effectively in order to be prepared for vocabulary on the TOEFL.