Let's take a quick peek at one of the most commonly bungled usage challenges: the difference between peak, peek and pique. A quick check of Google News left Mr. Rewrite feeling a bit peaked, to be honest.
Piquing Mr. Rewrite's interest in this subject: a reference to sneak peak by someone paid to know better. The writer, of course, meant sneak peek.
Here's the deal:
Peek means to peer, as in: He peeked in a window.
Among other things, peak means a pointed part, pointed top of a mountain and high point. That latter is why Mr. Rewrite doesn't want you to mistakenly write this: He peaked in a window. Ewwww.
Pique means to irritate or excite, as in: The book piqued his interest. This is commonly botched as "peaked." By the way, Mr. Rewrite considers the phrase "piqued the ire" hopelessly cliche and will slap, at least figuratively, any writer who uses it.
Meanwhile, peaked as an adjective means appearing sickly, pale and anemic. That's how Mr. Rewrite feels about two weeks into the semester. That meaning is frequently botched as piqued. Peaked as an adjective also can mean covered with peaks.