Correct sentences: "You are always on my mind." "You are always in my heart." "I always have you on my mind" "I always have you in my heart." These pretty much mean the same thing! Saying "always on my mind" means I'm always thinking of you. Saying "always in my heart" is more romantic." I would usually say "you're always on my mind" or "I'm always thinking of you." "I always have you on my mind" is a little formal; the other two are sweeter and friendlier in my opinion. Incorrect: "You are always in my mind." "I always have you in my mind." "In" is the wrong preposition. You have to use "on my mind." I hope that helped, at least a little bit! Hopefully some other people will chime in with different perspectives too :)