From Quora: My Answer to "Which method is considered the best for enhancing vocabulary in a short time for exam preparation and for the GRE exam?"
Learn Greek and Latin word roots, prefixes and suffixes. Googling “word roots, suffixes, and prefixes” will yield several useful websites that will let you “decode” words with Latin or Greek roots (i.e., most of the hard words on the GRE). You can also buy or borrow a copy of the Barron’s Essential Words for the GRE, which lists many words and has useful exercises to help you remember words. Good luck!
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Author: John Linneball Who did you think? ;-)
I'm the proprietor and only tutor for this business; that's why I named it after me.