We say “the fan is on” to express its current state.

and “the fan suddenly went on” to express an action.

Normally we use the simple past tense for an action because it happened.

if I say “the fan is going on”, it sounds strange because it just takes 1 second for the fan to go on.

I am sure we can say “the alarm clock is ringing” and “the alarm clock went off

But I am not sure if we can say “the alarm clock is going off

Can we say "The fire alarm is going off" to express the state of making sound?

And native English speakers say "The fire alarm is going off" see this Video

1 Answer 1


Yes, the alarm clock is going off, on its own, means it is making a sound. However the alarm clock is going off in five minutes means the sound will start in five minutes.

One way to understand the logic is that an alarm is "on" when it is in a "ready" state. When it is triggered it is no longer "ready", so it goes "off". At this time the alarm sound begins.

"The fan is going on" usually means it is starting or about to start.

  • so, you mean "the alarm clock is going off" is the same as "the alarm clock is ringing", right??? I thought "The alarm clock is off" means "the alarm clock is ringing"
    – Tom
    Sep 26, 2022 at 3:51
  • There is a big differece between "be off" and "go off". If "the alarm clock is off", then it isn't turned on and not telling the time nor making a sound. This is more critical with "alarm" since "The fire alarm is off" means that it is not functioning and not detecting fires.
    – James K
    Sep 26, 2022 at 5:40
  • The way I'd understand this is different. To "go off" means to depart on a journey (I went off to Paris at 9am) So "go off" can metaphorically mean "start to do the thing".
    – James K
    Sep 26, 2022 at 5:42
  • In the UK, milk goes off quickly on a warm day, if you don't put it in a refrigerator. Sep 26, 2022 at 7:30

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