Please could somebody tell me which sentence is correct?
What is on your mind? or
What is in your mind'
8 Answers
That depends on the context and what, exactly, you are asking.
If you are asking what a person is thinking about at the moment, the correct one is "... on your mind'"
If you are asking a person about the general contents of their mental processes, it is the other.
When your wondering what a person is thinking you would ask: What's ON your mind'
Sure, most of the time, if not quite 99.9%.
But I can think of some scenarios in which one would ask, "What is in your mind'" It may also be worded, "What do you have in mind'"
Overall, one is more likely to hear the question, "What is on your mind'"
Thank you for your kind help. I will use, What is on your mind'
Sure, most of the time, if not quite 99.9%.
But I can think of some scenarios in which one would ask, "What is in your mind'" It may also be worded, "What do you have in mind'"
Overall, one is more likely to hear the question, "What is on your mind'"
Agreed that "on your mind" is the most commonly used and is generally recognised as the correct expression. This appears strange as thoughts are not on your brain but in your brain.
We would also say "bear in mind"
I'd love to hear those senarios. 
Just teasing!
That depends on the context and what, exactly, you are asking.
If you are asking a person about the general contents of their mental processes, it is the other.
If I were asking you about the general contents of your mental process I's ask What is on your mind?
A psychiatrist would never ask "What's in your mind'". Don't overgeneralize things. 
The only thing close I could think of that sounds normal is if someone asks you What's going on in your head.
Look Rodolfo 99.9% of the time you'll use "What is on your mind'".
"What is on your mind'" is the correct one.
