grammar

[mimi]

what is the difference between the following questions?

Do you have it on you?

Do you have it with you?

[Marylin]

what is the difference between the following questions?

Do you have it on you?

Do you have it with you?

They mean the same thing, on being less formal than with.

[RonBee]

what is the difference between the following questions?

Do you have it on you?

Do you have it with you?

The first question asks if the person has the item on his person (perhaps in a pocket). The second question asks if the person has the item readily available (perhaps in a briefcase).