─ You can say that you have something on you if you are carrying it in your pocket or in a bag.
- I didn't have any money on me.
─ If you say that something is not on or is just not on, you mean that it is unacceptable or impossible. (mainly BRITISH INFORMAL)
- We shouldn't use the police in that way. It's just not on.
─ If something is on your mind, you are worried or concerned about it and think about it a lot.
- This game has been on my mind all week.
- I just forgot, I've had a lot on my mind.
─ If your mind is on something or you have your mind on something, you are thinking about that thing.
- At school I was always in trouble - my mind was never on my work.