+0
Whats the difference between in one's mind and on one's mind?

A. That's what she had in/on her mind.

B. I will always keep you in/on my mind.

C. What's on/in your mind? -- The answer is on, right? but why?
+0
If you search this forum you'll find a lot of information about this from other questions.

Basically, 'in mind' - something I am thinking about

'on my mind' - something I am worrying or fretting about. Something I'd rather not have to think about.
+0
Perhaps Nona was a little too restrictive - on my mind doesn't have to be an unpleasant thing. You are always on my mind COULD mean that I'm worrying about you, but it also can mean (and does in this song) that I think about you all the time.

Also, "in mind" (without the MY means) "intending or expecting."

Oh yes, that color scheme is exactly what I had in mind when I asked you to decorate the room.
Site Hint: Check out our list of pronunciation videos.
Comments  
Davidrock65
Whats the difference between in one's mind and on one's mind?

A. That's what she had in/on her mind. (My guess is that it woul be "in")

B. I will always keep you in/on my mind. (My guess is that it would be "in")

C. What's on/in your mind? -- The answer is on, right? but why? (I think it would be "on")

Why? This is my perspective on things.

Try to imagine what the person who raised that question might have been thinking when he/she asked/raised that question.

Let's delve into his delicate yet complex head of his/hers and see, if possible. what that person might have been thinking when that person asked that question. Normally a person will bring that form (sort) of question up when he/she is sensing something awry. That's why I think he/she would have used the preposition "on" and not "in."

What's on your mind? -- What is worrying you? What are you so occupied about?

What is in your mind? -- What are you thinking?

But why is there a song called "You are always on my mind," instead of "You are always in my mind?"
Students: Are you brave enough to let our tutors analyse your pronunciation?
Look at it this way. The title of the song "You are always on my mind" very well might refer to the notion that she/he is always occcupied by the thought of the one he/she loves.
 BarbaraPA's reply was promoted to an answer.