While my official title is “senior copywriter,” part of my job involves editing or proofreading others’ words—work that has done little to restore my hope in the American education system.
The worst offense—by far—is random capitalization. It’s bad, folks. I see people writing things like “The Company saw a 3% increase in revenue last year,” and “I earned a BS in Mathematics,” and “CK is President of the local chapter of the Donnie and Marie Fan Club.” (For the record, it’s company, mathematics, and president.)
Look, I understand that all the rules—and all the exceptions to all those rules—can be a little daunting. So just remember this one: Proper nouns (particular people, places, or things) are capitalized. Common nouns aren’t. That’s it.
Courtney traveled to San Diego via Amtrak’s Pacific Surfliner.
In this example, Courtney is a particular person who went to a particular place aboard a particular company’s particular conveyance (note that names of ships, trains, aircraft, and the like are usually italicized).
Swap all those proper nouns with common nouns, though, and you’ll get something like:
The woman took the train south.
See the difference? When it’s just a rando hitching a ride, the only thing you capitalize is the first word in the sentence.
If you find yourself questioning whether it’s a common or a proper noun, ask yourself if it’s the name of something or just the thing itself. If it’s the former, capitalize away. If not, don’t you dare hit that “shift” button.