back up

Separable

The object can go before or after the particle — but a pronoun MUST go in the middle: “clean it up”, never “clean up it”.

How to say it

Stress the particle, not the verb: back UP. Saying “BACK up” is the clearest learner tell — the verb stays light and the particle carries the beat.

Link across the gap. The final /k/ of “back” moves onto the particle and starts its syllable: “back up” is said “ba-ckup”. Pausing between the words is what makes phrasal verbs sound recited rather than spoken.

Verb vs noun

As a noun the stress flips to the front: the verb is back UP, the noun is BACKUP. Same two words, different beat — “to back UP” is the action, “a backup” is the thing. Getting this backwards makes the sentence land oddly even when every sound is right.

3 meanings

  1. 1

    To support someone or something with evidence or assistance.

    • He always backs up his arguments with solid evidence.
    • If I raise it in the meeting, will you back me up?

    Similar: support, corroborate

  2. 2

    To make a copy of computer data for safekeeping.

    • Back up your files before you install the update.
    • I back everything up to the cloud automatically.

    Similar: duplicate

  3. 3

    To move a vehicle backwards.

    • Back up a little — you're too close to the wall.
    • She backed the truck up to the loading dock.

    Similar: reverse

Don’t confuse it with

The particle logic

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Hear “back up” spoken naturally

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More BACK phrasal verbs

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back up — meaning, examples & how to say it