We begin a journey; dust causes an alarm to sound. Set off covers both. In the travel examples there is no direct object; in the alarm examples, the alarm is what is triggered.

The idea

For travel, use set off and add for a destination or on foot for how you travel. For triggering, use set off the alarm / set the alarm off, but set it off. The forms are set–set–set and setting.

Examples

  • We set off before the bakery opened.
  • Mina is setting off for the coast on Friday.
  • Omar set off on foot after breakfast.
  • Dust from the repair work set off the alarm.
  • Dust from the repair work set the alarm off.
  • The alarm was quiet until more dust set it off.

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Watch out

Setting an alarm off makes it start sounding; it does not turn it off. The particle off does not always mean stopping. Starting a journey also does not tell us that the destination was reached.

Try it yourself

  1. Choose the correct option. We ___ off before breakfast yesterday. (set / setted)

    Show answer or example answer

    set

    Set has the same base and past form: set, not setted.

  2. Choose the correct option. Mina is ___ off on Friday. (setting / seting)

    Show answer or example answer

    setting

    Double the final t before -ing: setting.

  3. Choose the correct option. The dust triggered the alarm: it set ___. (it off / off it)

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    it off

    The first it means the dust; the second replaces the alarm and goes between set and off.

Use it today

Describe when someone began a journey and where they were heading. Then name a cause that triggered an alarm, once with the noun and once with it.