* Simple: The book's excerpt was so intriguing, I had to buy the full version.
* With a specific context: The professor read an excerpt from Shakespeare's Hamlet to illustrate the theme of revenge.
* As a noun describing a specific action: The editor requested an excerpt of the chapter for the magazine's preview.
* As a verb: The author excerpted the most important parts of the book for the audiobook.
Let me know if you'd like to see some more examples or have a specific sentence in mind!