alarm go off

Meanings

1. 1phrasefixed phrase

   When an alarm goes off, it rings or sounds loudly to warn or wake people.

   Grammar: The alarm is the subject; 'go off' has no object, so say 'The alarm went off,' not 'The alarm went off the building.'

   Patterns

   • the alarm goes off
   • the alarm went off
   • the alarm will go off

   The fire alarm went off during the exam, so we all had to leave the building.

   My phone alarm goes off at seven every morning.

   If the smoke alarm goes off, check the kitchen first.

2. 2phrasefixed phrase

   When a warning device such as a car alarm or security alarm goes off, it starts making a loud noise, often by accident.

   Grammar: Same structure: the device is the subject and 'go off' means 'start sounding.'

   Patterns

   • a car alarm goes off
   • a security alarm went off
   • the alarm goes off by accident

   A car alarm went off in the parking lot and kept us awake.

   The security alarm went off because someone opened the back door.

   Our house alarm goes off if a window is broken.

Common combinations

the alarm goes off

The alarm goes off at six, so I get up early.

the alarm went off

The alarm went off just as I was leaving.

set the alarm to go off

I set the alarm to go off at 5:30.

a false alarm

The alarm went off, but it was a false alarm.

the fire alarm goes off

When the fire alarm goes off, use the stairs.

Synonyms and how they differ

ring

Use 'ring' for alarms, bells, and phones; 'go off' is very common for alarms but less natural for phones.

sound

'Sound' is more formal and can also be transitive ('sound the alarm'), while 'go off' is intransitive and informal.

activate

'Activate' is technical and usually transitive ('activate the alarm'), not used for the alarm starting by itself.

Word family

alarm noun

A device or warning sound that tells you about danger.

go off phrasal verb

To start ringing or sounding, used with alarms, bells, and sometimes guns.

Commonly confused: alarm go off or set off?

Practice

Make it your own

Write a sentence using “alarm go off”, then check it and compare it with the examples above.

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