Back up means to support a person or what they say, to support a claim with facts, or to make a copy of data. In an argument or a meeting, “back someone up” means to take their side. In an essay, “back up an argument” means to support a point with an example or figures, and “back up files” means to copy them in case something goes wrong.
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back + person + up; back up + claim/argument + with + evidence; back up + files/data; a backup (noun)
- When the client blamed me for the delay, my manager backed me up.
- I back up my photos to an external drive every Sunday evening.
- The researchers backed up their claims with data from three different countries.
What changed
First versionIn your essay, back up each idea by a real example.
RevisionIn your essay, back up each idea with a real example.
The thing you use to support an idea is introduced with “with”: “back up each idea with a real example”. “By” goes before an action with -ing (“back it up by giving an example”) and in passive sentences that name what provides the support: The claim is backed up by data.
“Back down” sounds similar but means almost the opposite: to give up your position in an argument. Compare: My colleagues backed me up, so I didn't back down.
Your turn
Before the system update, IT asked everyone to ___ their files.
Show the answer
back up — After “to”, you need an action, so the verb is written as two words: “to back up their files”. The single word “backup” is a noun or an adjective: make a backup, a backup copy.
Write a point for an essay about the advantages or disadvantages of remote work, and back it up with one specific example from your own experience.
Remote work can save a lot of time, and I can back this up with my own experience: I no longer spend ninety minutes a day on the bus.
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