"Can someone share what they use to <span style="text-decoration: underline;"><em>backup</em></span> their files?"

This was the subject line in an email to a Listserv I'm on. In this case, the person wrote backup (one word), which is an adjective, when he meant to say back up (two words), which is a verb.

There are several things about English that seem to trip up a lot of people. This is one of those things.

It happens when you have two words that are often used as a pair and you put them together in one word. However, the new word is not the same as the two-word pair. In some cases the two-word pair is a verb and the resulting new word is an adjective. In some cases the resulting word is a noun.

<strong>Back up is not the same as backup.</strong>

When back up is two words, there's some sort of action taking place, which means it's a verb. You put your car in reverse gear so you can <em>back up</em> (verb) out of your driveway. Maybe you <em>back up</em> (verb) your files on an external hard drive (I don't but I should). You <em>back up </em>(verb) your claims with proven information (although some presidential candidates don't).

When backup is one word, it can be an adjective, meaning the word is modifying or describing something. You may have a <em>backup </em>computer in case your usual computer conks out. You may have a <em>backup plan</em> in case something goes wrong. Sometimes, a backup is a noun:  You may have your<em> backup</em> with you on a thumb drive.

<strong>Shut down is not the same as shutdown.</strong>

At the end of your work day, perhaps you <em>shut down</em> (verb) your computer. Now your computer is in <em>shutdown </em>(adjective) mode.

This past Wednesday here in the Washington area, the Metro was <em>shut down</em> (verb) for more than 24 hours to conduct emergency inspections and repairs.  Metro's general manager said the <em>shutdown</em> (noun) was necessary.

<strong>Every day is not the same as everyday.</strong>

<em>Every day (noun)</em> that passes I think about some <em>everyday</em> (adjective) tasks that can get done quickly.

<span style="color: #ff0000;">Just some everyday information to pass on to you. Happy Friday!</span>

P.S. If you get tripped up with this type of thing in your documents, I can help fix it. Contact me about copy editing.