system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why does English do this?

We love to use opposite terms to describe things.  For example:

"The alarm went off." = "The alarm came on."  

Or, if you will tolerate a dirty example, angry hetero males routinely ask each other for gay sex before a fistfight. Example:

"Suck my c*ck!" 

Think about that request. The granting of that wish would mean a bad day for both parties.  I can't think of many other languages that celebrate such opposite expression.
gpt
> "The alarm went off." = "The alarm came on." 

Those are phrasal verbs, and they don't mean the same as the literal translations of their component parts. The alarm doesn't literally go to or come from anywhere.

To be honest, "The alarm went off" is much more usual: it means "was triggered". We use this of, for example, guns and bombs: "He picked up the grenade and it went off in his hands." We use it for alarms because we're thinking of something triggering it: depending on the type of alarm, it might be because a preset time has been reached, or because somebody pushed an emergency button, or because the system detected a fire, or whatever.

"Come on" means "begin to function". When we flick a light switch, the light (hopefully) comes on: electricity flows through it causing it to glow. We can only use this for actions that last a long time: guns and bombs explode instantaneously, so we can't say that they "come on". Talking about an alarm "coming on" isn't usual, but since the alarm sounds for a long period of time (until it is switched off), it's certainly possible.

So, "the alarm went off" means "the alarm was triggered"; but "the alarm came on" means "the alarm began to make a noise". It just so happens that in the case of alarms, those two things mean pretty much the same thing.