to know by heart
something you have memorized
To cross your heart and hope to die
To promise
To eat your heart out
To die of envy or jealousy
To be cold-hearted
Lacking in sympathy; to not be caring to others
to have a broken heart
to be very sad about something
To cry your heart out
To weep a lot and feel really badly about something
To take something to heart
To have your feelings hurt by something someone said or did
To have a heart of gold
To care about other people
To have your heart set on something
To really want something
To have a change of heart
To change your mind
From the bottom of your heart
To really mean something
To have a big heart
To be giving, caring
in a heart beat
very fast without waiting to think about it
To wear your heart on your sleeve
To let everyone know how you feel about something ; not hiding your feelings
To set your heart at rest
To stop worrying about something
To have your heart in your mouth
To be scared or nervous