PWN the SAT Q&A

Diction errors exploit weaknesses in your vocabulary (like using unintelligible to mean unintelligent) so the only real way to get better at spotting them is to bolster your vocabulary. However, unless you’re consistently scoring 770+ on writing, you really shouldn’t be focusing much of your energy on diction errors. You’ll see at most one on test day, and it’s quite possible you won’t see any.