have one’s mind on something—(also: keep one’s mind on something) give all one’s attention to smth.:
- It’s hard to work when you’ve got your mind on other things.
have something on one’s mind—think of smth. causing worry or concern:
- I knew my aunt sufficiently well to know that she had something of importance on her mind.
Note: The expression is not equivalent in meaning to the phrase have something in mind—
1. think about smth.; intend to do smth.:
- I didn’t know what he had in mind, so I just sat there waiting for him to tell me.
2. think of smth. as being suitable for some purpose:
- I have something in mind for the living-room carpeting.
See also: have something in one’s brain / have something on the brain.