Here are a few more examples. (I hope it helps.)
For the love of Pete!
He's batting three for five.
For whom does the bell toll?
This thingamajig is for turning up the volume.
For poison ivy, apply liberally to the foreskin...umm, the affected area.
Can you come over for an hour? For the night?
I'd like to make a reservation for dinner for six for (at) 8:00.
For dinner, we'd like fortified white bread.
What for?
For our health.
Thanks! That's quite a few. More than I was hoping for.
Is that really for me?
That's all there is for free. For any more you will have to pay.
As you can see, "for" is used in a variety of ways in quite a few different expressions.
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