2. To be cold hearted – you have to feel nothing as if you really dont care.

3. To cross your heart and hope to die – To prromise not to tell anyone this is mostly use in secrets where someone promise not to tell it to anyone else.

4. To eat your your heart out – (im not 100% sure) give it the best you can

5. To have a heart – to have the character to help others

6. To have your heart in your mouth – That you should speak what is in your heart, and say what you really feel.

7. To set your heart at rest – that you have to leave what has happened before and let it slip away and try forgetting something that hurt you

To have a change of heart – your right already

2. To be cold hearted means to be unfeeling and not care

3. To cross your heart and hope to die, means to promise vowing your life if you break your promise (not really though since children say this most often)

4. To eat your heart out means to be jealous of. For instance if I won the lottery I would say to my boss, Hey I just won the lottery and I quit, eat your heart out.

5. To have a heart is to show compassion. Usually you would ask someone to have a heart when you want their compasion

6. To have your heart in your mouth would be to have it be beating fast so it feels like it has moved up your throat to your mouth.

7. To set your heart at rest would be to find peace about an issue

8. The last is correct.

2. stubborn, hateful

3. promise with all your heart

5. be kind, compassionate