* have one's heart set on...一心想要……
Once he had his heart set on something, he'll accept no turning-back.
* one's heart in one's mouth吓得要命
My heart was in my mouth when I heart someone tapping on my window one raining night.
have one's heart in one's mouth; with one's heart in one's mouth
* not have the heart to do something不忍心去做
How can you have the heart to kill my pet?
* take something to heart往心里去/认真接受意见等
Tom decided to take his father's words to heart and wash his hands off smoking.