Here’s my favorite German compound word: Eisenbahnknotenpunkthinundherschieber, meaning a railroad switch operator. Literally, iron rail junction back-and-forth pusher.
Americans like to lump words together, too, though to a lesser degree and often with less precision, unfortunately. When the same series of letters can change its meaning because of the absence or presence of a space (i.e., whether they’re offered as one word or two), it’s best to take care and make sure you’re clear.
Three examples follow:
Goodwill vs. good will
On this point, I go along with the Associated Press Stylebook. As one word, it has a specific meaning used when one company buys another. Per AP style: “…the amount by which the purchase price exceeds the fair value of an acquired company’s net assets.”
The two-word form refers to a sense of benevolence: “Myron’s a contemptible skunk, but he fractured his fibula while trampolining, so this month I’ll mow his lawn in a show of good will.”
Unless you’re working on a business story or a financial report, you’re most likely to want good will. (And here’s hoping you get it. See how benevolent that was?)
Underway vs. under way