Avoid vocabulary mistakes with this fun guide to tricky and troublesome words!   With concise and authoritative usage notes from the editors of the American Heritage® Dictionaries, this guide explains common English-language errors—whether it’s mixing up affect and effect; blatant and flagrant; or disinterested and uninterested, or stumbling over sound-alikes including discrete/discreet or principal/principle.   Other notes tackle such classic irritants as hopefully, impact, and aggravate, as well as problematic words like peruse and presently.   A great read for anyone who cares about getting it right, 100 Words Almost Everyone Confuses and Misuses can help keep writers and speakers on the up-and-up!