It's essential to have a good vocabulary to do well in the TOEFL exam. These four strategies explain how you can effectively increase your vocabulary as you study for TOEFL.
1. Increase your academic vocabulary to understand 95% - 98% of a text
The more words you know, the more clearly you'll understand what you're reading or listening to.
To really understand academic texts (like the reading and listening passages in TOEFL) and to be able to answer the questions, you should have between 95% - 98% comprehension. That means you have a handful of words in each reading passage or each lecture that you don't know, but that's it.
If you only have 80% - 90% understanding, you're probably missing important points and this will make it much harder for you to answer the questions correctly. So, work on increasing your overall academic vocabulary.
Let's consider which sorts of words you should learn, and why you should focus on those categories.
The image shows an analysis of two categories of language. Remember, we want to aim for at least 95% comprehension.
Look at the math! If you know the 2,000 most frequent words in English AND academic vocabulary, that takes you to an 87% understanding. The other 8% (to get you to a 95% comprehension) will come from lower frequency words.
That's why you should concentrate on learning high frequency vocabulary. It includes most of the function words in English such as prepositions, determiners and auxiliary verbs. These are tricky to learn but - as you can see from the image - it's really worth the effort.
Also, look at the 'conversations' column - the kind of language you use in TOEFL speaking task 1. A very high percentage of vocabulary in conversations is high frequency vocabulary too, so that's what you should concentrate on learning.
The third way to think about what vocabulary to learn, is to understand the difference between receptive vocabulary and productive vocabulary.
Receptive Vocabulary = all the vocabulary you understand when you encounter it
Productive Vocabulary = the vocabulary you use in your own speaking and writing
In most cases, for most people, receptive vocabulary is larger than productive vocabulary (R > P).
So, words that you understand the meaning of, but don't use, (your receptive vocabulary) can - with practice - be transferred to your productive vocabulary. This makes sense because you are already familiar with their meanings; you just need to practice using them in speaking and writing.
Of course, there will be many words that stay in your receptive vocabulary but any increase in your productive vocabulary means you'll be able to explain yourself more clearly (and faster too, which is a definite benefit for TOEFL!).
This is probably the most important strategy of the four.
Vocabulary research tells us that we need to repeat a word many, many times before it stays in our heads and becomes part of our productive vocabulary. How many repetitions? That depends on a few different factors, but somewhere between 7 and 20 is average.
And don't just repeat these words the same way all the time. Type them, speak them and actually use them, and you'll learn faster.