You can't memorize every word, but you can learn to decode unfamiliar ones by knowing common roots, prefixes, and suffixes. This single strategy can unlock thousands of words you've never explicitly studied.
Take the root bene- (good) and mal- (bad). Once you know these, you can reason through new words: benevolent (well-wishing, kind), benefactor, beneficial — all carry that sense of goodness. Meanwhile, malicious (intending harm), malevolent, malfunction — all signal something negative.
PrepScholar's SAT vocabulary guide shows that many high-frequency test words share common Latin and Greek roots. Learning about 50 common roots gives you a foothold with words you've never seen before.
Here's the key insight: when you encounter ambivalent on the test, knowing that ambi- means "both" immediately tells you it involves two sides — two conflicting feelings. You don't need a perfect definition to choose the right answer; you need enough signal to eliminate wrong choices.
Start with 5 roots per week. Write each root on a card with 3-4 example words. Within a month, you'll have a decoding toolkit that works on test day even when the exact word wasn't in your study deck. That's the power of building vocabulary from the roots up.